diff --git a/CHANGELOG.md b/CHANGELOG.md
index 492adaf9..bb027c55 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@
 - Minor benchmark script improvements #2768 (@cyqsimon)
 - Update Arch Linux package URL in README files #2779 (@brunobell)
 - Update and improve `zsh` completion, see #2772 (@okapia)
+- More extensible syntax mapping mechanism #2755 (@cyqsimon)
 - Use proper Architecture for Debian packages built for musl, see #2811 (@Enselic)
 - Pull in fix for unsafe-libyaml security advisory, see #2812 (@dtolnay)
 - Update git-version dependency to use Syn v2, see #2816 (@dtolnay)
@@ -28,6 +29,10 @@
 
 ## `bat` as a library
 
+- Changes to `syntax_mapping::SyntaxMapping` #2755 (@cyqsimon)
+  - `SyntaxMapping::get_syntax_for` is now correctly public
+  - [BREAKING] `SyntaxMapping::{empty,builtin}` are removed; use `SyntaxMapping::new` instead
+  - [BREAKING] `SyntaxMapping::mappings` is replaced by `SyntaxMapping::{builtin,custom,all}_mappings`
 - Make `Controller::run_with_error_handler`'s error handler `FnMut`, see #2831 (@rhysd)
 
 # v0.24.0
diff --git a/Cargo.lock b/Cargo.lock
index 19ee5928..4aaf7b32 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -129,6 +129,8 @@ dependencies = [
  "globset",
  "grep-cli",
  "home",
+ "indexmap 2.1.0",
+ "itertools",
  "nix",
  "nu-ansi-term",
  "once_cell",
@@ -140,12 +142,14 @@ dependencies = [
  "run_script",
  "semver",
  "serde",
+ "serde_with",
  "serde_yaml",
  "serial_test",
  "shell-words",
  "syntect",
  "tempfile",
  "thiserror",
+ "toml",
  "unicode-width",
  "wait-timeout",
  "walkdir",
@@ -224,11 +228,12 @@ checksum = "a3e368af43e418a04d52505cf3dbc23dda4e3407ae2fa99fd0e4f308ce546acc"
 
 [[package]]
 name = "cc"
-version = "1.0.73"
+version = "1.0.83"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2fff2a6927b3bb87f9595d67196a70493f627687a71d87a0d692242c33f58c11"
+checksum = "f1174fb0b6ec23863f8b971027804a42614e347eafb0a95bf0b12cdae21fc4d0"
 dependencies = [
  "jobserver",
+ "libc",
 ]
 
 [[package]]
@@ -314,6 +319,41 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "darling"
+version = "0.20.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0209d94da627ab5605dcccf08bb18afa5009cfbef48d8a8b7d7bdbc79be25c5e"
+dependencies = [
+ "darling_core",
+ "darling_macro",
+]
+
+[[package]]
+name = "darling_core"
+version = "0.20.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "177e3443818124b357d8e76f53be906d60937f0d3a90773a664fa63fa253e621"
+dependencies = [
+ "fnv",
+ "ident_case",
+ "proc-macro2",
+ "quote",
+ "strsim",
+ "syn",
+]
+
+[[package]]
+name = "darling_macro"
+version = "0.20.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "836a9bbc7ad63342d6d6e7b815ccab164bc77a2d95d84bc3117a8c0d5c98e2d5"
+dependencies = [
+ "darling_core",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "dashmap"
 version = "5.4.0"
@@ -578,6 +618,12 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
+[[package]]
+name = "ident_case"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"
+
 [[package]]
 name = "idna"
 version = "0.3.0"
@@ -600,12 +646,13 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "2.0.2"
+version = "2.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8adf3ddd720272c6ea8bf59463c04e0f93d0bbf7c5439b691bca2987e0270897"
+checksum = "d530e1a18b1cb4c484e6e34556a0d948706958449fca0cab753d649f2bce3d1f"
 dependencies = [
  "equivalent",
  "hashbrown 0.14.1",
+ "serde",
 ]
 
 [[package]]
@@ -1101,13 +1148,44 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "serde_spanned"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "12022b835073e5b11e90a14f86838ceb1c8fb0325b72416845c487ac0fa95e80"
+dependencies = [
+ "serde",
+]
+
+[[package]]
+name = "serde_with"
+version = "3.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "64cd236ccc1b7a29e7e2739f27c0b2dd199804abc4290e32f59f3b68d6405c23"
+dependencies = [
+ "serde",
+ "serde_with_macros",
+]
+
+[[package]]
+name = "serde_with_macros"
+version = "3.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93634eb5f75a2323b16de4748022ac4297f9e76b6dced2be287a099f41b5e788"
+dependencies = [
+ "darling",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "serde_yaml"
 version = "0.9.29"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a15e0ef66bf939a7c890a0bf6d5a733c70202225f9888a89ed5c62298b019129"
 dependencies = [
- "indexmap 2.0.2",
+ "indexmap 2.1.0",
  "itoa",
  "ryu",
  "serde",
@@ -1294,6 +1372,41 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cda74da7e1a664f795bb1f8a87ec406fb89a02522cf6e50620d016add6dbbf5c"
 
+[[package]]
+name = "toml"
+version = "0.8.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ff9e3abce27ee2c9a37f9ad37238c1bdd4e789c84ba37df76aa4d528f5072cc"
+dependencies = [
+ "indexmap 2.1.0",
+ "serde",
+ "serde_spanned",
+ "toml_datetime",
+ "toml_edit",
+]
+
+[[package]]
+name = "toml_datetime"
+version = "0.6.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3550f4e9685620ac18a50ed434eb3aec30db8ba93b0287467bca5826ea25baf1"
+dependencies = [
+ "serde",
+]
+
+[[package]]
+name = "toml_edit"
+version = "0.20.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "70f427fce4d84c72b5b732388bf4a9f4531b53f74e2887e3ecb2481f68f66d81"
+dependencies = [
+ "indexmap 2.1.0",
+ "serde",
+ "serde_spanned",
+ "toml_datetime",
+ "winnow",
+]
+
 [[package]]
 name = "unicode-bidi"
 version = "0.3.8"
@@ -1613,6 +1726,15 @@ version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dff9641d1cd4be8d1a070daf9e3773c5f67e78b4d9d42263020c057706765c04"
 
+[[package]]
+name = "winnow"
+version = "0.5.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "176b6138793677221d420fd2f0aeeced263f197688b36484660da767bca2fa32"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "yaml-rust"
 version = "0.4.5"
diff --git a/Cargo.toml b/Cargo.toml
index 53bc2da4..3b7f10e6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -100,6 +100,14 @@ nix = { version = "0.26.4", default-features = false, features = ["term"] }
 
 [build-dependencies]
 anyhow = "1.0.78"
+indexmap = { version = "2.1.0", features = ["serde"] }
+itertools = "0.11.0"
+once_cell = "1.18"
+regex = "1.10.2"
+serde = { version = "1.0", features = ["derive"] }
+serde_with = { version = "3.4.0", default-features = false, features = ["macros"] }
+toml = { version = "0.8.6", features = ["preserve_order"] }
+walkdir = "2.4"
 
 [build-dependencies.clap]
 version = "4.4.12"
diff --git a/build/main.rs b/build/main.rs
index 416d90d5..8966ee52 100644
--- a/build/main.rs
+++ b/build/main.rs
@@ -1,5 +1,6 @@
 #[cfg(feature = "application")]
 mod application;
+mod syntax_mapping;
 mod util;
 
 fn main() -> anyhow::Result<()> {
@@ -7,6 +8,8 @@ fn main() -> anyhow::Result<()> {
     // see: https://doc.rust-lang.org/cargo/reference/build-scripts.html#rerun-if-changed
     println!("cargo:rerun-if-changed=build/");
 
+    syntax_mapping::build_static_mappings()?;
+
     #[cfg(feature = "application")]
     application::gen_man_and_comp()?;
 
diff --git a/build/syntax_mapping.rs b/build/syntax_mapping.rs
new file mode 100644
index 00000000..c29b9225
--- /dev/null
+++ b/build/syntax_mapping.rs
@@ -0,0 +1,292 @@
+use std::{
+    convert::Infallible,
+    env, fs,
+    path::{Path, PathBuf},
+    str::FromStr,
+};
+
+use anyhow::{anyhow, bail};
+use indexmap::IndexMap;
+use itertools::Itertools;
+use once_cell::sync::Lazy;
+use regex::Regex;
+use serde::Deserialize;
+use serde_with::DeserializeFromStr;
+use walkdir::WalkDir;
+
+/// Known mapping targets.
+///
+/// Corresponds to `syntax_mapping::MappingTarget`.
+#[allow(clippy::enum_variant_names)]
+#[derive(Clone, Debug, Eq, PartialEq, Hash, DeserializeFromStr)]
+pub enum MappingTarget {
+    MapTo(String),
+    MapToUnknown,
+    MapExtensionToUnknown,
+}
+impl FromStr for MappingTarget {
+    type Err = Infallible;
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "MappingTarget::MapToUnknown" => Ok(Self::MapToUnknown),
+            "MappingTarget::MapExtensionToUnknown" => Ok(Self::MapExtensionToUnknown),
+            syntax => Ok(Self::MapTo(syntax.into())),
+        }
+    }
+}
+impl MappingTarget {
+    fn codegen(&self) -> String {
+        match self {
+            Self::MapTo(syntax) => format!(r###"MappingTarget::MapTo(r#"{syntax}"#)"###),
+            Self::MapToUnknown => "MappingTarget::MapToUnknown".into(),
+            Self::MapExtensionToUnknown => "MappingTarget::MapExtensionToUnknown".into(),
+        }
+    }
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Hash, DeserializeFromStr)]
+/// A single matcher.
+///
+/// Codegen converts this into a `Lazy<Option<GlobMatcher>>`.
+struct Matcher(Vec<MatcherSegment>);
+/// Parse a matcher.
+///
+/// Note that this implementation is rather strict: it will greedily interpret
+/// every valid environment variable replacement as such, then immediately
+/// hard-error if it finds a '$', '{', or '}' anywhere in the remaining text
+/// segments.
+///
+/// The reason for this strictness is I currently cannot think of a valid reason
+/// why you would ever need '$', '{', or '}' as plaintext in a glob pattern.
+/// Therefore any such occurrences are likely human errors.
+///
+/// If we later discover some edge cases, it's okay to make it more permissive.
+impl FromStr for Matcher {
+    type Err = anyhow::Error;
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        use MatcherSegment as Seg;
+        static VAR_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"\$\{([\w\d_]+)\}").unwrap());
+
+        let mut segments = vec![];
+        let mut text_start = 0;
+        for capture in VAR_REGEX.captures_iter(s) {
+            let match_0 = capture.get(0).unwrap();
+
+            // text before this var
+            let text_end = match_0.start();
+            segments.push(Seg::Text(s[text_start..text_end].into()));
+            text_start = match_0.end();
+
+            // this var
+            segments.push(Seg::Env(capture.get(1).unwrap().as_str().into()));
+        }
+        // possible trailing text
+        segments.push(Seg::Text(s[text_start..].into()));
+
+        // cleanup empty text segments
+        let non_empty_segments = segments
+            .into_iter()
+            .filter(|seg| seg.text().map(|t| !t.is_empty()).unwrap_or(true))
+            .collect_vec();
+
+        // sanity check
+        if non_empty_segments
+            .windows(2)
+            .any(|segs| segs[0].is_text() && segs[1].is_text())
+        {
+            unreachable!("Parsed into consecutive text segments: {non_empty_segments:?}");
+        }
+
+        // guard empty case
+        if non_empty_segments.is_empty() {
+            bail!(r#"Parsed an empty matcher: "{s}""#);
+        }
+
+        // guard variable syntax leftover fragments
+        if non_empty_segments
+            .iter()
+            .filter_map(Seg::text)
+            .any(|t| t.contains(['$', '{', '}']))
+        {
+            bail!(r#"Invalid matcher: "{s}""#);
+        }
+
+        Ok(Self(non_empty_segments))
+    }
+}
+impl Matcher {
+    fn codegen(&self) -> String {
+        match self.0.len() {
+            0 => unreachable!("0-length matcher should never be created"),
+            // if-let guard would be ideal here
+            // see: https://github.com/rust-lang/rust/issues/51114
+            1 if self.0[0].is_text() => {
+                let s = self.0[0].text().unwrap();
+                format!(r###"Lazy::new(|| Some(build_matcher_fixed(r#"{s}"#)))"###)
+            }
+            // parser logic ensures that this case can only happen when there are dynamic segments
+            _ => {
+                let segs = self.0.iter().map(MatcherSegment::codegen).join(", ");
+                format!(r###"Lazy::new(|| build_matcher_dynamic(&[{segs}]))"###)
+            }
+        }
+    }
+}
+
+/// A segment in a matcher.
+///
+/// Corresponds to `syntax_mapping::MatcherSegment`.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+enum MatcherSegment {
+    Text(String),
+    Env(String),
+}
+#[allow(dead_code)]
+impl MatcherSegment {
+    fn is_text(&self) -> bool {
+        matches!(self, Self::Text(_))
+    }
+    fn is_env(&self) -> bool {
+        matches!(self, Self::Env(_))
+    }
+    fn text(&self) -> Option<&str> {
+        match self {
+            Self::Text(t) => Some(t),
+            Self::Env(_) => None,
+        }
+    }
+    fn env(&self) -> Option<&str> {
+        match self {
+            Self::Text(_) => None,
+            Self::Env(t) => Some(t),
+        }
+    }
+    fn codegen(&self) -> String {
+        match self {
+            Self::Text(s) => format!(r###"MatcherSegment::Text(r#"{s}"#)"###),
+            Self::Env(s) => format!(r###"MatcherSegment::Env(r#"{s}"#)"###),
+        }
+    }
+}
+
+/// A struct that models a single .toml file in /src/syntax_mapping/builtins/.
+#[derive(Clone, Debug, Deserialize)]
+struct MappingDefModel {
+    mappings: IndexMap<MappingTarget, Vec<Matcher>>,
+}
+impl MappingDefModel {
+    fn into_mapping_list(self) -> MappingList {
+        let list = self
+            .mappings
+            .into_iter()
+            .flat_map(|(target, matchers)| {
+                matchers
+                    .into_iter()
+                    .map(|matcher| (matcher, target.clone()))
+                    .collect::<Vec<_>>()
+            })
+            .collect();
+        MappingList(list)
+    }
+}
+
+#[derive(Clone, Debug)]
+struct MappingList(Vec<(Matcher, MappingTarget)>);
+impl MappingList {
+    fn codegen(&self) -> String {
+        let array_items: Vec<_> = self
+            .0
+            .iter()
+            .map(|(matcher, target)| {
+                format!("({m}, {t})", m = matcher.codegen(), t = target.codegen())
+            })
+            .collect();
+        let len = array_items.len();
+
+        format!(
+            "/// Generated by build script from /src/syntax_mapping/builtins/.\n\
+            pub(crate) static BUILTIN_MAPPINGS: [(Lazy<Option<GlobMatcher>>, MappingTarget); {len}] = [\n{items}\n];",
+            items = array_items.join(",\n")
+        )
+    }
+}
+
+/// Get the list of paths to all mapping definition files that should be
+/// included for the current target platform.
+fn get_def_paths() -> anyhow::Result<Vec<PathBuf>> {
+    let source_subdirs = [
+        "common",
+        #[cfg(target_family = "unix")]
+        "unix-family",
+        #[cfg(any(
+            target_os = "freebsd",
+            target_os = "netbsd",
+            target_os = "openbsd",
+            target_os = "macos"
+        ))]
+        "bsd-family",
+        #[cfg(target_os = "linux")]
+        "linux",
+        #[cfg(target_os = "macos")]
+        "macos",
+        #[cfg(target_os = "windows")]
+        "windows",
+    ];
+
+    let mut toml_paths = vec![];
+    for subdir in source_subdirs {
+        let wd = WalkDir::new(Path::new("src/syntax_mapping/builtins").join(subdir));
+        let paths = wd
+            .into_iter()
+            .filter_map_ok(|entry| {
+                let path = entry.path();
+                (path.is_file() && path.extension().map(|ext| ext == "toml").unwrap_or(false))
+                    .then(|| path.to_owned())
+            })
+            .collect::<Result<Vec<_>, _>>()?;
+        toml_paths.extend(paths);
+    }
+
+    toml_paths.sort_by_key(|path| {
+        path.file_name()
+            .expect("file name should not terminate in ..")
+            .to_owned()
+    });
+
+    Ok(toml_paths)
+}
+
+fn read_all_mappings() -> anyhow::Result<MappingList> {
+    let mut all_mappings = vec![];
+
+    for path in get_def_paths()? {
+        let toml_string = fs::read_to_string(path)?;
+        let mappings = toml::from_str::<MappingDefModel>(&toml_string)?.into_mapping_list();
+        all_mappings.extend(mappings.0);
+    }
+
+    let duplicates = all_mappings
+        .iter()
+        .duplicates_by(|(matcher, _)| matcher)
+        .collect_vec();
+    if !duplicates.is_empty() {
+        bail!("Rules with duplicate matchers found: {duplicates:?}");
+    }
+
+    Ok(MappingList(all_mappings))
+}
+
+/// Build the static syntax mappings defined in /src/syntax_mapping/builtins/
+/// into a .rs source file, which is to be inserted with `include!`.
+pub fn build_static_mappings() -> anyhow::Result<()> {
+    println!("cargo:rerun-if-changed=src/syntax_mapping/builtins/");
+
+    let mappings = read_all_mappings()?;
+
+    let codegen_path = Path::new(&env::var_os("OUT_DIR").ok_or(anyhow!("OUT_DIR is unset"))?)
+        .join("codegen_static_syntax_mappings.rs");
+
+    fs::write(codegen_path, mappings.codegen())?;
+
+    Ok(())
+}
diff --git a/src/assets.rs b/src/assets.rs
index 7ce1a8f6..0129f76b 100644
--- a/src/assets.rs
+++ b/src/assets.rs
@@ -441,7 +441,7 @@ mod tests {
         fn new() -> Self {
             SyntaxDetectionTest {
                 assets: HighlightingAssets::from_binary(),
-                syntax_mapping: SyntaxMapping::builtin(),
+                syntax_mapping: SyntaxMapping::new(),
                 temp_dir: TempDir::new().expect("creation of temporary directory"),
             }
         }
diff --git a/src/bin/bat/app.rs b/src/bin/bat/app.rs
index 09430623..a2c09770 100644
--- a/src/bin/bat/app.rs
+++ b/src/bin/bat/app.rs
@@ -121,7 +121,7 @@ impl App {
             _ => unreachable!("other values for --paging are not allowed"),
         };
 
-        let mut syntax_mapping = SyntaxMapping::builtin();
+        let mut syntax_mapping = SyntaxMapping::new();
 
         if let Some(values) = self.matches.get_many::<String>("ignored-suffix") {
             for suffix in values {
@@ -130,7 +130,9 @@ impl App {
         }
 
         if let Some(values) = self.matches.get_many::<String>("map-syntax") {
-            for from_to in values {
+            // later args take precedence over earlier ones, hence `.rev()`
+            // see: https://github.com/sharkdp/bat/pull/2755#discussion_r1456416875
+            for from_to in values.rev() {
                 let parts: Vec<_> = from_to.split(':').collect();
 
                 if parts.len() != 2 {
diff --git a/src/bin/bat/main.rs b/src/bin/bat/main.rs
index 43e9d288..f48abdc1 100644
--- a/src/bin/bat/main.rs
+++ b/src/bin/bat/main.rs
@@ -78,9 +78,11 @@ fn run_cache_subcommand(
     Ok(())
 }
 
-fn get_syntax_mapping_to_paths<'a>(
-    mappings: &[(GlobMatcher, MappingTarget<'a>)],
-) -> HashMap<&'a str, Vec<String>> {
+fn get_syntax_mapping_to_paths<'r, 't, I>(mappings: I) -> HashMap<&'t str, Vec<String>>
+where
+    I: IntoIterator<Item = (&'r GlobMatcher, &'r MappingTarget<'t>)>,
+    't: 'r, // target text outlives rule
+{
     let mut map = HashMap::new();
     for mapping in mappings {
         if let (matcher, MappingTarget::MapTo(s)) = mapping {
@@ -123,7 +125,7 @@ pub fn get_languages(config: &Config, cache_dir: &Path) -> Result<String> {
 
     languages.sort_by_key(|lang| lang.name.to_uppercase());
 
-    let configured_languages = get_syntax_mapping_to_paths(config.syntax_mapping.mappings());
+    let configured_languages = get_syntax_mapping_to_paths(config.syntax_mapping.all_mappings());
 
     for lang in &mut languages {
         if let Some(additional_paths) = configured_languages.get(lang.name.as_str()) {
diff --git a/src/syntax_mapping.rs b/src/syntax_mapping.rs
index c8c361ab..0dac0c02 100644
--- a/src/syntax_mapping.rs
+++ b/src/syntax_mapping.rs
@@ -1,12 +1,23 @@
 use std::path::Path;
 
-use crate::error::Result;
-use ignored_suffixes::IgnoredSuffixes;
-
 use globset::{Candidate, GlobBuilder, GlobMatcher};
 
+use crate::error::Result;
+use builtin::BUILTIN_MAPPINGS;
+use ignored_suffixes::IgnoredSuffixes;
+
+mod builtin;
 pub mod ignored_suffixes;
 
+fn make_glob_matcher(from: &str) -> Result<GlobMatcher> {
+    let matcher = GlobBuilder::new(from)
+        .case_insensitive(true)
+        .literal_separator(true)
+        .build()?
+        .compile_matcher();
+    Ok(matcher)
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 #[non_exhaustive]
 pub enum MappingTarget<'a> {
@@ -29,204 +40,72 @@ pub enum MappingTarget<'a> {
 
 #[derive(Debug, Clone, Default)]
 pub struct SyntaxMapping<'a> {
-    mappings: Vec<(GlobMatcher, MappingTarget<'a>)>,
+    /// User-defined mappings at run time.
+    ///
+    /// Rules in front have precedence.
+    custom_mappings: Vec<(GlobMatcher, MappingTarget<'a>)>,
     pub(crate) ignored_suffixes: IgnoredSuffixes<'a>,
 }
 
 impl<'a> SyntaxMapping<'a> {
-    pub fn empty() -> SyntaxMapping<'a> {
+    pub fn new() -> SyntaxMapping<'a> {
         Default::default()
     }
 
-    pub fn builtin() -> SyntaxMapping<'a> {
-        let mut mapping = Self::empty();
-        mapping.insert("*.h", MappingTarget::MapTo("C++")).unwrap();
-        mapping
-            .insert(".clang-format", MappingTarget::MapTo("YAML"))
-            .unwrap();
-        mapping.insert("*.fs", MappingTarget::MapTo("F#")).unwrap();
-        mapping
-            .insert("build", MappingTarget::MapToUnknown)
-            .unwrap();
-        mapping
-            .insert("**/.ssh/config", MappingTarget::MapTo("SSH Config"))
-            .unwrap();
-        mapping
-            .insert(
-                "**/bat/config",
-                MappingTarget::MapTo("Bourne Again Shell (bash)"),
-            )
-            .unwrap();
-        mapping
-            .insert(
-                "/etc/profile",
-                MappingTarget::MapTo("Bourne Again Shell (bash)"),
-            )
-            .unwrap();
-        mapping
-            .insert(
-                "os-release",
-                MappingTarget::MapTo("Bourne Again Shell (bash)"),
-            )
-            .unwrap();
-        mapping
-            .insert("*.pac", MappingTarget::MapTo("JavaScript (Babel)"))
-            .unwrap();
-        mapping
-            .insert("fish_history", MappingTarget::MapTo("YAML"))
-            .unwrap();
-
-        for glob in ["*.jsonl", "*.sarif"] {
-            mapping.insert(glob, MappingTarget::MapTo("JSON")).unwrap();
-        }
-
-        // See #2151, https://nmap.org/book/nse-language.html
-        mapping
-            .insert("*.nse", MappingTarget::MapTo("Lua"))
-            .unwrap();
-
-        // See #1008
-        mapping
-            .insert("rails", MappingTarget::MapToUnknown)
-            .unwrap();
-
-        mapping
-            .insert("Containerfile", MappingTarget::MapTo("Dockerfile"))
-            .unwrap();
-
-        mapping
-            .insert("*.ksh", MappingTarget::MapTo("Bourne Again Shell (bash)"))
-            .unwrap();
-
-        // Nginx and Apache syntax files both want to style all ".conf" files
-        // see #1131 and #1137
-        mapping
-            .insert("*.conf", MappingTarget::MapExtensionToUnknown)
-            .unwrap();
-
-        for glob in &[
-            "/etc/nginx/**/*.conf",
-            "/etc/nginx/sites-*/**/*",
-            "nginx.conf",
-            "mime.types",
-        ] {
-            mapping.insert(glob, MappingTarget::MapTo("nginx")).unwrap();
-        }
-
-        for glob in &[
-            "/etc/apache2/**/*.conf",
-            "/etc/apache2/sites-*/**/*",
-            "httpd.conf",
-        ] {
-            mapping
-                .insert(glob, MappingTarget::MapTo("Apache Conf"))
-                .unwrap();
-        }
-
-        for glob in &[
-            "**/systemd/**/*.conf",
-            "**/systemd/**/*.example",
-            "*.automount",
-            "*.device",
-            "*.dnssd",
-            "*.link",
-            "*.mount",
-            "*.netdev",
-            "*.network",
-            "*.nspawn",
-            "*.path",
-            "*.service",
-            "*.scope",
-            "*.slice",
-            "*.socket",
-            "*.swap",
-            "*.target",
-            "*.timer",
-        ] {
-            mapping.insert(glob, MappingTarget::MapTo("INI")).unwrap();
-        }
-
-        // unix mail spool
-        for glob in &["/var/spool/mail/*", "/var/mail/*"] {
-            mapping.insert(glob, MappingTarget::MapTo("Email")).unwrap()
-        }
-
-        // pacman hooks
-        mapping
-            .insert("*.hook", MappingTarget::MapTo("INI"))
-            .unwrap();
-
-        mapping
-            .insert("*.ron", MappingTarget::MapTo("Rust"))
-            .unwrap();
-
-        // Global git config files rooted in `$XDG_CONFIG_HOME/git/` or `$HOME/.config/git/`
-        // See e.g. https://git-scm.com/docs/git-config#FILES
-        match (
-            std::env::var_os("XDG_CONFIG_HOME").filter(|val| !val.is_empty()),
-            std::env::var_os("HOME")
-                .filter(|val| !val.is_empty())
-                .map(|home| Path::new(&home).join(".config")),
-        ) {
-            (Some(xdg_config_home), Some(default_config_home))
-                if xdg_config_home == default_config_home => {
-                insert_git_config_global(&mut mapping, &xdg_config_home)
-            }
-            (Some(xdg_config_home), Some(default_config_home)) /* else guard */ => {
-                insert_git_config_global(&mut mapping, &xdg_config_home);
-                insert_git_config_global(&mut mapping, &default_config_home)
-            }
-            (Some(config_home), None) => insert_git_config_global(&mut mapping, &config_home),
-            (None, Some(config_home)) => insert_git_config_global(&mut mapping, &config_home),
-            (None, None) => (),
-        };
-
-        fn insert_git_config_global(mapping: &mut SyntaxMapping, config_home: impl AsRef<Path>) {
-            let git_config_path = config_home.as_ref().join("git");
-
-            mapping
-                .insert(
-                    &git_config_path.join("config").to_string_lossy(),
-                    MappingTarget::MapTo("Git Config"),
-                )
-                .ok();
-
-            mapping
-                .insert(
-                    &git_config_path.join("ignore").to_string_lossy(),
-                    MappingTarget::MapTo("Git Ignore"),
-                )
-                .ok();
-
-            mapping
-                .insert(
-                    &git_config_path.join("attributes").to_string_lossy(),
-                    MappingTarget::MapTo("Git Attributes"),
-                )
-                .ok();
-        }
-
-        mapping
-    }
-
     pub fn insert(&mut self, from: &str, to: MappingTarget<'a>) -> Result<()> {
-        let glob = GlobBuilder::new(from)
-            .case_insensitive(true)
-            .literal_separator(true)
-            .build()?;
-        self.mappings.push((glob.compile_matcher(), to));
+        let matcher = make_glob_matcher(from)?;
+        self.custom_mappings.push((matcher, to));
         Ok(())
     }
 
-    pub fn mappings(&self) -> &[(GlobMatcher, MappingTarget<'a>)] {
-        &self.mappings
+    /// Returns an iterator over all mappings. User-defined mappings are listed
+    /// before builtin mappings; mappings in front have higher precedence.
+    ///
+    /// Builtin mappings' `GlobMatcher`s are lazily compiled.
+    ///
+    /// Note that this function only returns mappings that are valid under the
+    /// current environment. For details see [`Self::builtin_mappings`].
+    pub fn all_mappings(&self) -> impl Iterator<Item = (&GlobMatcher, &MappingTarget<'a>)> {
+        self.custom_mappings()
+            .iter()
+            .map(|(matcher, target)| (matcher, target)) // as_ref
+            .chain(
+                // we need a map with a closure to "do" the lifetime variance
+                // see: https://discord.com/channels/273534239310479360/1120124565591425034/1170543402870382653
+                // also, clippy false positive:
+                // see: https://github.com/rust-lang/rust-clippy/issues/9280
+                #[allow(clippy::map_identity)]
+                self.builtin_mappings().map(|rule| rule),
+            )
     }
 
-    pub(crate) fn get_syntax_for(&self, path: impl AsRef<Path>) -> Option<MappingTarget<'a>> {
+    /// Returns an iterator over all valid builtin mappings. Mappings in front
+    /// have higher precedence.
+    ///
+    /// The `GlabMatcher`s are lazily compiled.
+    ///
+    /// Mappings that are invalid under the current environment (i.e. rule
+    /// requires environment variable(s) that is unset, or the joined string
+    /// after variable(s) replacement is not a valid glob expression) are
+    /// ignored.
+    pub fn builtin_mappings(
+        &self,
+    ) -> impl Iterator<Item = (&'static GlobMatcher, &'static MappingTarget<'static>)> {
+        BUILTIN_MAPPINGS
+            .iter()
+            .filter_map(|(matcher, target)| matcher.as_ref().map(|glob| (glob, target)))
+    }
+
+    /// Returns all user-defined mappings.
+    pub fn custom_mappings(&self) -> &[(GlobMatcher, MappingTarget<'a>)] {
+        &self.custom_mappings
+    }
+
+    pub fn get_syntax_for(&self, path: impl AsRef<Path>) -> Option<MappingTarget<'a>> {
         // Try matching on the file name as-is.
         let candidate = Candidate::new(&path);
         let candidate_filename = path.as_ref().file_name().map(Candidate::new);
-        for (ref glob, ref syntax) in self.mappings.iter().rev() {
+        for (glob, syntax) in self.all_mappings() {
             if glob.is_match_candidate(&candidate)
                 || candidate_filename
                     .as_ref()
@@ -252,9 +131,46 @@ impl<'a> SyntaxMapping<'a> {
 #[cfg(test)]
 mod tests {
     use super::*;
+
     #[test]
-    fn basic() {
-        let mut map = SyntaxMapping::empty();
+    fn builtin_mappings_work() {
+        let map = SyntaxMapping::new();
+
+        assert_eq!(
+            map.get_syntax_for("/path/to/build"),
+            Some(MappingTarget::MapToUnknown)
+        );
+    }
+
+    #[test]
+    fn all_fixed_builtin_mappings_can_compile() {
+        let map = SyntaxMapping::new();
+
+        // collect call evaluates all lazy closures
+        // fixed builtin mappings will panic if they fail to compile
+        let _mappings = map.builtin_mappings().collect::<Vec<_>>();
+    }
+
+    #[test]
+    fn builtin_mappings_matcher_only_compile_once() {
+        let map = SyntaxMapping::new();
+
+        let two_iterations: Vec<_> = (0..2)
+            .map(|_| {
+                // addresses of every matcher
+                map.builtin_mappings()
+                    .map(|(matcher, _)| matcher as *const _ as usize)
+                    .collect::<Vec<_>>()
+            })
+            .collect();
+
+        // if the matchers are only compiled once, their address should remain the same
+        assert_eq!(two_iterations[0], two_iterations[1]);
+    }
+
+    #[test]
+    fn custom_mappings_work() {
+        let mut map = SyntaxMapping::new();
         map.insert("/path/to/Cargo.lock", MappingTarget::MapTo("TOML"))
             .ok();
         map.insert("/path/to/.ignore", MappingTarget::MapTo("Git Ignore"))
@@ -273,52 +189,32 @@ mod tests {
     }
 
     #[test]
-    fn user_can_override_builtin_mappings() {
-        let mut map = SyntaxMapping::builtin();
+    fn custom_mappings_override_builtin() {
+        let mut map = SyntaxMapping::new();
 
         assert_eq!(
-            map.get_syntax_for("/etc/profile"),
-            Some(MappingTarget::MapTo("Bourne Again Shell (bash)"))
+            map.get_syntax_for("/path/to/httpd.conf"),
+            Some(MappingTarget::MapTo("Apache Conf"))
         );
-        map.insert("/etc/profile", MappingTarget::MapTo("My Syntax"))
+        map.insert("httpd.conf", MappingTarget::MapTo("My Syntax"))
             .ok();
         assert_eq!(
-            map.get_syntax_for("/etc/profile"),
+            map.get_syntax_for("/path/to/httpd.conf"),
             Some(MappingTarget::MapTo("My Syntax"))
         );
     }
 
     #[test]
-    fn builtin_mappings() {
-        let map = SyntaxMapping::builtin();
+    fn custom_mappings_precedence() {
+        let mut map = SyntaxMapping::new();
 
+        map.insert("/path/to/foo", MappingTarget::MapTo("alpha"))
+            .ok();
+        map.insert("/path/to/foo", MappingTarget::MapTo("bravo"))
+            .ok();
         assert_eq!(
-            map.get_syntax_for("/path/to/build"),
-            Some(MappingTarget::MapToUnknown)
+            map.get_syntax_for("/path/to/foo"),
+            Some(MappingTarget::MapTo("alpha"))
         );
     }
-
-    #[test]
-    /// verifies that SyntaxMapping::builtin() doesn't repeat `Glob`-based keys
-    fn no_duplicate_builtin_keys() {
-        let mappings = SyntaxMapping::builtin().mappings;
-        for i in 0..mappings.len() {
-            let tail = mappings[i + 1..].into_iter();
-            let (dupl, _): (Vec<_>, Vec<_>) =
-                tail.partition(|item| item.0.glob() == mappings[i].0.glob());
-
-            // emit repeats on failure
-            assert_eq!(
-                dupl.len(),
-                0,
-                "Glob pattern `{}` mapped to multiple: {:?}",
-                mappings[i].0.glob().glob(),
-                {
-                    let (_, mut dupl_targets): (Vec<GlobMatcher>, Vec<MappingTarget>) =
-                        dupl.into_iter().cloned().unzip();
-                    dupl_targets.push(mappings[i].1)
-                },
-            )
-        }
-    }
 }
diff --git a/src/syntax_mapping/builtin.rs b/src/syntax_mapping/builtin.rs
new file mode 100644
index 00000000..1822be57
--- /dev/null
+++ b/src/syntax_mapping/builtin.rs
@@ -0,0 +1,91 @@
+use std::env;
+
+use globset::GlobMatcher;
+use once_cell::sync::Lazy;
+
+use crate::syntax_mapping::{make_glob_matcher, MappingTarget};
+
+// Static syntax mappings generated from /src/syntax_mapping/builtins/ by the
+// build script (/build/syntax_mapping.rs).
+include!(concat!(
+    env!("OUT_DIR"),
+    "/codegen_static_syntax_mappings.rs"
+));
+
+// The defined matcher strings are analysed at compile time and converted into
+// lazily-compiled `GlobMatcher`s. This is so that the string searches are moved
+// from run time to compile time, thus improving startup performance.
+//
+// To any future maintainer (including possibly myself) wondering why there is
+// not a `BuiltinMatcher` enum that looks like this:
+//
+// ```
+// enum BuiltinMatcher {
+//     Fixed(&'static str),
+//     Dynamic(Lazy<Option<String>>),
+// }
+// ```
+//
+// Because there was. I tried it and threw it out.
+//
+// Naively looking at the problem from a distance, this may seem like a good
+// design (strongly typed etc. etc.). It would also save on compiled size by
+// extracting out common behaviour into functions. But while actually
+// implementing the lazy matcher compilation logic, I realised that it's most
+// convenient for `BUILTIN_MAPPINGS` to have the following type:
+//
+// `[(Lazy<Option<GlobMatcher>>, MappingTarget); N]`
+//
+// The benefit for this is that operations like listing all builtin mappings
+// would be effectively memoised. The caller would not have to compile another
+// `GlobMatcher` for rules that they have previously visited.
+//
+// Unfortunately, this means we are going to have to store a distinct closure
+// for each rule anyway, which makes a `BuiltinMatcher` enum a pointless layer
+// of indirection.
+//
+// In the current implementation, the closure within each generated rule simply
+// calls either `build_matcher_fixed` or `build_matcher_dynamic`, depending on
+// whether the defined matcher contains dynamic segments or not.
+
+/// Compile a fixed glob string into a glob matcher.
+///
+/// A failure to compile is a fatal error.
+///
+/// Used internally by `Lazy<Option<GlobMatcher>>`'s lazy evaluation closure.
+fn build_matcher_fixed(from: &str) -> GlobMatcher {
+    make_glob_matcher(from).expect("A builtin fixed glob matcher failed to compile")
+}
+
+/// Join a list of matcher segments to create a glob string, replacing all
+/// environment variables, then compile to a glob matcher.
+///
+/// Returns `None` if any replacement fails, or if the joined glob string fails
+/// to compile.
+///
+/// Used internally by `Lazy<Option<GlobMatcher>>`'s lazy evaluation closure.
+fn build_matcher_dynamic(segs: &[MatcherSegment]) -> Option<GlobMatcher> {
+    // join segments
+    let mut buf = String::new();
+    for seg in segs {
+        match seg {
+            MatcherSegment::Text(s) => buf.push_str(s),
+            MatcherSegment::Env(var) => {
+                let replaced = env::var(var).ok()?;
+                buf.push_str(&replaced);
+            }
+        }
+    }
+    // compile glob matcher
+    let matcher = make_glob_matcher(&buf).ok()?;
+    Some(matcher)
+}
+
+/// A segment of a dynamic builtin matcher.
+///
+/// Used internally by `Lazy<Option<GlobMatcher>>`'s lazy evaluation closure.
+#[derive(Clone, Debug)]
+enum MatcherSegment {
+    Text(&'static str),
+    Env(&'static str),
+}
diff --git a/src/syntax_mapping/builtins/README.md b/src/syntax_mapping/builtins/README.md
new file mode 100644
index 00000000..29cf43ee
--- /dev/null
+++ b/src/syntax_mapping/builtins/README.md
@@ -0,0 +1,116 @@
+# `/src/syntax_mapping/builtins`
+
+The files in this directory define path/name-based syntax mappings, which amend
+and take precedence over the extension/content-based syntax mappings provided by
+[syntect](https://github.com/trishume/syntect).
+
+## File organisation
+
+Each TOML file should describe the syntax mappings of a single application, or
+otherwise a set of logically-related rules.
+
+What defines "a single application" here is deliberately vague, since the
+file-splitting is purely for maintainability reasons. (Technically, we could
+just as well use a single TOML file.) So just use common sense.
+
+TOML files should reside in the corresponding subdirectory of the platform(s)
+that they intend to target. At compile time, the build script will go through
+each subdirectory that is applicable to the compilation target, collect the
+syntax mappings defined by all TOML files, and embed them into the binary.
+
+## File syntax
+
+Each TOML file should contain a single section named `mappings`, with each of
+its keys being a language identifier (first column of `bat -L`; also referred to
+as "target").
+
+The value of each key should be an array of strings, with each item being a glob
+matcher. We will call each of these items a "rule".
+
+For example, if `foo-application` uses both TOML and YAML configuration files,
+we could write something like this:
+
+```toml
+# 30-foo-application.toml
+[mappings]
+"TOML" = [
+    # rules for TOML syntax go here
+    "/usr/share/foo-application/toml-config/*.conf",
+    "/etc/foo-application/toml-config/*.conf",
+]
+"YAML" = [
+    # rules for YAML syntax go here
+    # ...
+]
+```
+
+### Dynamic environment variable replacement
+
+In additional to the standard glob matcher syntax, rules also support dynamic
+replacement of environment variables at runtime. This allows us to concisely
+handle things like [XDG](https://specifications.freedesktop.org/basedir-spec/latest/).
+
+All environment variables intended to be replaced at runtime must be enclosed in
+`${}`, for example `"/foo/*/${YOUR_ENV}-suffix/*.log"`. Note that this is the
+**only** admissible syntax; other variable substitution syntaxes are not
+supported and will either cause a compile time error, or be treated as plain
+text.
+
+For example, if `foo-application` also supports per-user configuration files, we
+could write something like this:
+
+```toml
+# 30-foo-application.toml
+[mappings]
+"TOML" = [
+    # rules for TOML syntax go here
+    "/usr/share/foo-application/toml-config/*.conf",
+    "/etc/foo-application/toml-config/*.conf",
+    "${XDG_CONFIG_HOME}/foo-application/toml-config/*.conf",
+    "${HOME}/.config/foo-application/toml-config/*.conf",
+]
+"YAML" = [
+    # rules for YAML syntax go here
+    # ...
+]
+```
+
+If any environment variable replacement in a rule fails (for example when a
+variable is unset), or if the glob string after replacements is invalid, the
+entire rule will be ignored.
+
+### Explicitly mapping to unknown
+
+Sometimes it may be necessary to "unset" a particular syntect mapping - perhaps
+a syntax's matching rules are "too greedy", and is claiming files that it should
+not. In this case, there are two special identifiers:
+`MappingTarget::MapToUnknown` and `MappingTarget::MapExtensionToUnknown`
+(corresponding to the two variants of the `syntax_mapping::MappingTarget` enum).
+
+An example of this would be `*.conf` files in general. So we may write something
+like this:
+
+```toml
+# 99-unset-ambiguous-extensions.toml
+[mappings]
+"MappingTarget::MapExtensionToUnknown" = [
+    "*.conf",
+]
+```
+
+## Ordering
+
+At compile time, all TOML files applicable to the target are processed in
+lexicographical filename order. So `00-foo.toml` takes precedence over
+`10-bar.toml`, which takes precedence over `20-baz.toml`, and so on. Note that
+**only** the filenames of the TOML files are taken into account; the
+subdirectories they are placed in have no influence on ordering.
+
+This behaviour can be occasionally useful for creating high/low priority rules,
+such as in the aforementioned example of explicitly mapping `*.conf` files to
+unknown. Generally this should not be much of a concern though, since rules
+should be written as specifically as possible for each application.
+
+Rules within each TOML file are processed (and therefore matched) in the order
+in which they are defined. At runtime, the syntax selection algorithm will
+short-circuit and return the target of the first matching rule.
diff --git a/src/syntax_mapping/builtins/bsd-family/.gitkeep b/src/syntax_mapping/builtins/bsd-family/.gitkeep
new file mode 100644
index 00000000..e69de29b
diff --git a/src/syntax_mapping/builtins/bsd-family/50-os-release.toml b/src/syntax_mapping/builtins/bsd-family/50-os-release.toml
new file mode 100644
index 00000000..91b003d7
--- /dev/null
+++ b/src/syntax_mapping/builtins/bsd-family/50-os-release.toml
@@ -0,0 +1,2 @@
+[mappings]
+"Bourne Again Shell (bash)" = ["/etc/os-release", "/var/run/os-release"]
diff --git a/src/syntax_mapping/builtins/common/.gitkeep b/src/syntax_mapping/builtins/common/.gitkeep
new file mode 100644
index 00000000..e69de29b
diff --git a/src/syntax_mapping/builtins/common/50-apache.toml b/src/syntax_mapping/builtins/common/50-apache.toml
new file mode 100644
index 00000000..0e557aff
--- /dev/null
+++ b/src/syntax_mapping/builtins/common/50-apache.toml
@@ -0,0 +1,2 @@
+[mappings]
+"Apache Conf" = ["httpd.conf"]
diff --git a/src/syntax_mapping/builtins/common/50-bat.toml b/src/syntax_mapping/builtins/common/50-bat.toml
new file mode 100644
index 00000000..e70b6b09
--- /dev/null
+++ b/src/syntax_mapping/builtins/common/50-bat.toml
@@ -0,0 +1,2 @@
+[mappings]
+"Bourne Again Shell (bash)" = ["**/bat/config"]
diff --git a/src/syntax_mapping/builtins/common/50-container.toml b/src/syntax_mapping/builtins/common/50-container.toml
new file mode 100644
index 00000000..ad48c29b
--- /dev/null
+++ b/src/syntax_mapping/builtins/common/50-container.toml
@@ -0,0 +1,2 @@
+[mappings]
+"Dockerfile" = ["Containerfile"]
diff --git a/src/syntax_mapping/builtins/common/50-cpp.toml b/src/syntax_mapping/builtins/common/50-cpp.toml
new file mode 100644
index 00000000..99d8a32b
--- /dev/null
+++ b/src/syntax_mapping/builtins/common/50-cpp.toml
@@ -0,0 +1,6 @@
+[mappings]
+"C++" = [
+    # probably better than the default Objective C mapping #877
+    "*.h",
+]
+"YAML" = [".clang-format"]
diff --git a/src/syntax_mapping/builtins/common/50-f-sharp.toml b/src/syntax_mapping/builtins/common/50-f-sharp.toml
new file mode 100644
index 00000000..a39e7ebd
--- /dev/null
+++ b/src/syntax_mapping/builtins/common/50-f-sharp.toml
@@ -0,0 +1,2 @@
+[mappings]
+"F#" = ["*.fs"]
diff --git a/src/syntax_mapping/builtins/common/50-git.toml b/src/syntax_mapping/builtins/common/50-git.toml
new file mode 100644
index 00000000..44a49a25
--- /dev/null
+++ b/src/syntax_mapping/builtins/common/50-git.toml
@@ -0,0 +1,10 @@
+# Global git config files rooted in `$XDG_CONFIG_HOME/git/` or `$HOME/.config/git/`
+# See e.g. https://git-scm.com/docs/git-config#FILES
+
+[mappings]
+"Git Config" = ["${XDG_CONFIG_HOME}/git/config", "${HOME}/.config/git/config"]
+"Git Ignore" = ["${XDG_CONFIG_HOME}/git/ignore", "${HOME}/.config/git/ignore"]
+"Git Attributes" = [
+    "${XDG_CONFIG_HOME}/git/attributes",
+    "${HOME}/.config/git/attributes",
+]
diff --git a/src/syntax_mapping/builtins/common/50-jsonl.toml b/src/syntax_mapping/builtins/common/50-jsonl.toml
new file mode 100644
index 00000000..4b70a4d0
--- /dev/null
+++ b/src/syntax_mapping/builtins/common/50-jsonl.toml
@@ -0,0 +1,3 @@
+# JSON Lines is a simple variation of JSON #2535
+[mappings]
+"JSON" = ["*.jsonl"]
diff --git a/src/syntax_mapping/builtins/common/50-nginx.toml b/src/syntax_mapping/builtins/common/50-nginx.toml
new file mode 100644
index 00000000..305418bb
--- /dev/null
+++ b/src/syntax_mapping/builtins/common/50-nginx.toml
@@ -0,0 +1,2 @@
+[mappings]
+"nginx" = ["nginx.conf", "mime.types"]
diff --git a/src/syntax_mapping/builtins/common/50-nmap.toml b/src/syntax_mapping/builtins/common/50-nmap.toml
new file mode 100644
index 00000000..f79a5e97
--- /dev/null
+++ b/src/syntax_mapping/builtins/common/50-nmap.toml
@@ -0,0 +1,3 @@
+[mappings]
+# See #2151, https://nmap.org/book/nse-language.html
+"Lua" = ["*.nse"]
diff --git a/src/syntax_mapping/builtins/common/50-proxy-auto-config.toml b/src/syntax_mapping/builtins/common/50-proxy-auto-config.toml
new file mode 100644
index 00000000..70e51c92
--- /dev/null
+++ b/src/syntax_mapping/builtins/common/50-proxy-auto-config.toml
@@ -0,0 +1,3 @@
+# 1515
+[mappings]
+"JavaScript (Babel)" = ["*.pac"]
diff --git a/src/syntax_mapping/builtins/common/50-ron.toml b/src/syntax_mapping/builtins/common/50-ron.toml
new file mode 100644
index 00000000..bc04221b
--- /dev/null
+++ b/src/syntax_mapping/builtins/common/50-ron.toml
@@ -0,0 +1,3 @@
+# Rusty Object Notation #2427
+[mappings]
+"Rust" = ["*.ron"]
diff --git a/src/syntax_mapping/builtins/common/50-sarif.toml b/src/syntax_mapping/builtins/common/50-sarif.toml
new file mode 100644
index 00000000..2542b9cd
--- /dev/null
+++ b/src/syntax_mapping/builtins/common/50-sarif.toml
@@ -0,0 +1,3 @@
+# SARIF is a format for reporting static analysis results #2695
+[mappings]
+"JSON" = ["*.sarif"]
diff --git a/src/syntax_mapping/builtins/common/50-ssh.toml b/src/syntax_mapping/builtins/common/50-ssh.toml
new file mode 100644
index 00000000..6ec24050
--- /dev/null
+++ b/src/syntax_mapping/builtins/common/50-ssh.toml
@@ -0,0 +1,2 @@
+[mappings]
+"SSH Config" = ["**/.ssh/config"]
diff --git a/src/syntax_mapping/builtins/common/99-unset-ambiguous-extensions.toml b/src/syntax_mapping/builtins/common/99-unset-ambiguous-extensions.toml
new file mode 100644
index 00000000..d87537d7
--- /dev/null
+++ b/src/syntax_mapping/builtins/common/99-unset-ambiguous-extensions.toml
@@ -0,0 +1,5 @@
+[mappings]
+"MappingTarget::MapExtensionToUnknown" = [
+    # common extension used for all kinds of formats
+    "*.conf",
+]
diff --git a/src/syntax_mapping/builtins/common/99-unset-ambiguous-filenames.toml b/src/syntax_mapping/builtins/common/99-unset-ambiguous-filenames.toml
new file mode 100644
index 00000000..21941ebc
--- /dev/null
+++ b/src/syntax_mapping/builtins/common/99-unset-ambiguous-filenames.toml
@@ -0,0 +1,7 @@
+[mappings]
+"MappingTarget::MapToUnknown" = [
+    # "NAnt Build File" should only match *.build files, not files named "build"
+    "build",
+    # "bin/rails" scripts in a Ruby project misidentified as HTML (Rails) #1008
+    "rails",
+]
diff --git a/src/syntax_mapping/builtins/linux/.gitkeep b/src/syntax_mapping/builtins/linux/.gitkeep
new file mode 100644
index 00000000..e69de29b
diff --git a/src/syntax_mapping/builtins/linux/50-os-release.toml b/src/syntax_mapping/builtins/linux/50-os-release.toml
new file mode 100644
index 00000000..791599aa
--- /dev/null
+++ b/src/syntax_mapping/builtins/linux/50-os-release.toml
@@ -0,0 +1,7 @@
+[mappings]
+"Bourne Again Shell (bash)" = [
+    "/etc/os-release",
+    "/usr/lib/os-release",
+    "/etc/initrd-release",
+    "/usr/lib/extension-release.d/extension-release.*",
+]
diff --git a/src/syntax_mapping/builtins/linux/50-pacman.toml b/src/syntax_mapping/builtins/linux/50-pacman.toml
new file mode 100644
index 00000000..655118c5
--- /dev/null
+++ b/src/syntax_mapping/builtins/linux/50-pacman.toml
@@ -0,0 +1,3 @@
+[mappings]
+# pacman hooks
+"INI" = ["/usr/share/libalpm/hooks/*.hook", "/etc/pacman.d/hooks/*.hook"]
diff --git a/src/syntax_mapping/builtins/linux/50-systemd.toml b/src/syntax_mapping/builtins/linux/50-systemd.toml
new file mode 100644
index 00000000..6f91b0be
--- /dev/null
+++ b/src/syntax_mapping/builtins/linux/50-systemd.toml
@@ -0,0 +1,21 @@
+[mappings]
+"INI" = [
+    "**/systemd/**/*.conf",
+    "**/systemd/**/*.example",
+    "*.automount",
+    "*.device",
+    "*.dnssd",
+    "*.link",
+    "*.mount",
+    "*.netdev",
+    "*.network",
+    "*.nspawn",
+    "*.path",
+    "*.service",
+    "*.scope",
+    "*.slice",
+    "*.socket",
+    "*.swap",
+    "*.target",
+    "*.timer",
+]
diff --git a/src/syntax_mapping/builtins/macos/.gitkeep b/src/syntax_mapping/builtins/macos/.gitkeep
new file mode 100644
index 00000000..e69de29b
diff --git a/src/syntax_mapping/builtins/unix-family/.gitkeep b/src/syntax_mapping/builtins/unix-family/.gitkeep
new file mode 100644
index 00000000..e69de29b
diff --git a/src/syntax_mapping/builtins/unix-family/50-apache.toml b/src/syntax_mapping/builtins/unix-family/50-apache.toml
new file mode 100644
index 00000000..dfb920f3
--- /dev/null
+++ b/src/syntax_mapping/builtins/unix-family/50-apache.toml
@@ -0,0 +1,2 @@
+[mappings]
+"Apache Conf" = ["/etc/apache2/**/*.conf", "/etc/apache2/sites-*/**/*"]
diff --git a/src/syntax_mapping/builtins/unix-family/50-fish-shell.toml b/src/syntax_mapping/builtins/unix-family/50-fish-shell.toml
new file mode 100644
index 00000000..f2a9e224
--- /dev/null
+++ b/src/syntax_mapping/builtins/unix-family/50-fish-shell.toml
@@ -0,0 +1,2 @@
+[mappings]
+"YAML" = ["fish_history"]
diff --git a/src/syntax_mapping/builtins/unix-family/50-korn-shell.toml b/src/syntax_mapping/builtins/unix-family/50-korn-shell.toml
new file mode 100644
index 00000000..6c788d1d
--- /dev/null
+++ b/src/syntax_mapping/builtins/unix-family/50-korn-shell.toml
@@ -0,0 +1,3 @@
+# KornShell is backward-compatible with the Bourne shell #2633
+[mappings]
+"Bourne Again Shell (bash)" = ["*.ksh"]
diff --git a/src/syntax_mapping/builtins/unix-family/50-mail-spool.toml b/src/syntax_mapping/builtins/unix-family/50-mail-spool.toml
new file mode 100644
index 00000000..c798358c
--- /dev/null
+++ b/src/syntax_mapping/builtins/unix-family/50-mail-spool.toml
@@ -0,0 +1,2 @@
+[mappings]
+"Email" = ["/var/spool/mail/*", "/var/mail/*"]
diff --git a/src/syntax_mapping/builtins/unix-family/50-nginx.toml b/src/syntax_mapping/builtins/unix-family/50-nginx.toml
new file mode 100644
index 00000000..580b65d8
--- /dev/null
+++ b/src/syntax_mapping/builtins/unix-family/50-nginx.toml
@@ -0,0 +1,2 @@
+[mappings]
+"nginx" = ["/etc/nginx/**/*.conf", "/etc/nginx/sites-*/**/*"]
diff --git a/src/syntax_mapping/builtins/unix-family/50-shell.toml b/src/syntax_mapping/builtins/unix-family/50-shell.toml
new file mode 100644
index 00000000..d015ca81
--- /dev/null
+++ b/src/syntax_mapping/builtins/unix-family/50-shell.toml
@@ -0,0 +1,5 @@
+[mappings]
+"Bourne Again Shell (bash)" = [
+    # used by lots of shells
+    "/etc/profile",
+]
diff --git a/src/syntax_mapping/builtins/windows/.gitkeep b/src/syntax_mapping/builtins/windows/.gitkeep
new file mode 100644
index 00000000..e69de29b
diff --git a/tests/benchmarks/run-benchmarks.sh b/tests/benchmarks/run-benchmarks.sh
index 0f43bc6b..2809ccbb 100755
--- a/tests/benchmarks/run-benchmarks.sh
+++ b/tests/benchmarks/run-benchmarks.sh
@@ -9,6 +9,13 @@ if ! command -v hyperfine > /dev/null 2>&1; then
 	exit 1
 fi
 
+# Check that jq is installed.
+if ! command -v jq > /dev/null 2>&1; then
+	echo "'jq' does not seem to be installed."
+	echo "You can get it here: https://jqlang.github.io/jq/download/"
+	exit 1
+fi
+
 # Check that python3 is installed.
 if ! command -v python3 > /dev/null 2>&1; then
 	echo "'python3' does not seem to be installed."
@@ -95,10 +102,20 @@ hyperfine \
 cat "$RESULT_DIR/startup-time.md" >> "$REPORT"
 
 
+heading "Startup time without syntax highlighting"
+hyperfine \
+	"$(printf "%q" "$BAT") --no-config startup-time-src/small-CpuInfo-file.cpuinfo" \
+	--command-name "bat … small-CpuInfo-file.cpuinfo" \
+	--warmup "$WARMUP_COUNT" \
+    --runs "$RUN_COUNT" \
+    --export-markdown "$RESULT_DIR/startup-time-without-syntax-highlighting.md" \
+    --export-json "$RESULT_DIR/startup-time-without-syntax-highlighting.json"
+cat "$RESULT_DIR/startup-time-without-syntax-highlighting.md" >> "$REPORT"
+
 heading "Startup time with syntax highlighting"
 hyperfine \
 	"$(printf "%q" "$BAT") --no-config --color=always startup-time-src/small-CpuInfo-file.cpuinfo" \
-	--command-name "bat … small-CpuInfo-file.cpuinfo" \
+	--command-name "bat … --color=always small-CpuInfo-file.cpuinfo" \
 	--warmup "$WARMUP_COUNT" \
     --runs "$RUN_COUNT" \
     --export-markdown "$RESULT_DIR/startup-time-with-syntax-highlighting.md" \
@@ -117,6 +134,40 @@ hyperfine \
 cat "$RESULT_DIR/startup-time-with-syntax-with-dependencies.md" >> "$REPORT"
 
 
+heading "Startup time with indeterminant syntax"
+hyperfine \
+	"$(printf "%q" "$BAT") --no-config --color=always startup-time-src/mystery-file" \
+	--shell none \
+	--command-name 'bat … mystery-file' \
+	--warmup "$WARMUP_COUNT" \
+    --runs "$RUN_COUNT" \
+    --export-markdown "$RESULT_DIR/startup-time-with-indeterminant-syntax.md" \
+    --export-json "$RESULT_DIR/startup-time-with-indeterminant-syntax.json"
+cat "$RESULT_DIR/startup-time-with-indeterminant-syntax.md" >> "$REPORT"
+
+heading "Startup time with manually set syntax"
+hyperfine \
+	"$(printf "%q" "$BAT") --no-config --color=always --language=Dockerfile startup-time-src/mystery-file" \
+	--shell none \
+	--command-name 'bat … --language=Dockerfile mystery-file' \
+	--warmup "$WARMUP_COUNT" \
+    --runs "$RUN_COUNT" \
+    --export-markdown "$RESULT_DIR/startup-time-with-manually-set-syntax.md" \
+    --export-json "$RESULT_DIR/startup-time-with-manually-set-syntax.json"
+cat "$RESULT_DIR/startup-time-with-manually-set-syntax.md" >> "$REPORT"
+
+heading "Startup time with mapped syntax"
+hyperfine \
+	"$(printf "%q" "$BAT") --no-config --color=always startup-time-src/Containerfile" \
+	--shell none \
+	--command-name 'bat … Containerfile' \
+	--warmup "$WARMUP_COUNT" \
+    --runs "$RUN_COUNT" \
+    --export-markdown "$RESULT_DIR/startup-time-with-mapped-syntax.md" \
+    --export-json "$RESULT_DIR/startup-time-with-mapped-syntax.json"
+cat "$RESULT_DIR/startup-time-with-mapped-syntax.md" >> "$REPORT"
+
+
 heading "Plain-text speed"
 hyperfine \
 	"$(printf "%q" "$BAT") --no-config --language=txt --style=plain highlighting-speed-src/numpy_test_multiarray.py" \
diff --git a/tests/benchmarks/startup-time-src/Containerfile b/tests/benchmarks/startup-time-src/Containerfile
new file mode 100644
index 00000000..a93ce851
--- /dev/null
+++ b/tests/benchmarks/startup-time-src/Containerfile
@@ -0,0 +1,3 @@
+FROM docker.io/alpine:latest
+COPY foo /root/bar
+RUN sleep 60
diff --git a/tests/benchmarks/startup-time-src/mystery-file b/tests/benchmarks/startup-time-src/mystery-file
new file mode 100644
index 00000000..a93ce851
--- /dev/null
+++ b/tests/benchmarks/startup-time-src/mystery-file
@@ -0,0 +1,3 @@
+FROM docker.io/alpine:latest
+COPY foo /root/bar
+RUN sleep 60