diff --git a/crates/language/src/buffer.rs b/crates/language/src/buffer.rs
index 7c616762d8..b7a1bd30fc 100644
--- a/crates/language/src/buffer.rs
+++ b/crates/language/src/buffer.rs
@@ -2496,7 +2496,7 @@ impl Drop for QueryCursorHandle {
     }
 }
 
-trait ToTreeSitterPoint {
+pub(crate) trait ToTreeSitterPoint {
     fn to_ts_point(self) -> tree_sitter::Point;
     fn from_ts_point(point: tree_sitter::Point) -> Self;
 }
diff --git a/crates/language/src/language.rs b/crates/language/src/language.rs
index fbcc983df9..8dcfc8fffd 100644
--- a/crates/language/src/language.rs
+++ b/crates/language/src/language.rs
@@ -3,6 +3,7 @@ mod diagnostic_set;
 mod highlight_map;
 mod outline;
 pub mod proto;
+mod syntax_map;
 #[cfg(test)]
 mod tests;
 
@@ -290,9 +291,17 @@ pub struct Grammar {
     pub(crate) brackets_query: Option<Query>,
     pub(crate) indents_query: Option<Query>,
     pub(crate) outline_query: Option<Query>,
+    pub(crate) injection_config: Option<InjectionConfig>,
     pub(crate) highlight_map: Mutex<HighlightMap>,
 }
 
+struct InjectionConfig {
+    query: Query,
+    content_capture_ix: u32,
+    language_capture_ix: Option<u32>,
+    languages_by_pattern_ix: Vec<Option<Box<str>>>,
+}
+
 #[derive(Clone)]
 pub enum LanguageServerBinaryStatus {
     CheckingForUpdate,
@@ -571,6 +580,7 @@ impl Language {
                     brackets_query: None,
                     indents_query: None,
                     outline_query: None,
+                    injection_config: None,
                     ts_language,
                     highlight_map: Default::default(),
                 })
@@ -610,6 +620,40 @@ impl Language {
         Ok(self)
     }
 
+    pub fn with_injection_query(mut self, source: &str) -> Result<Self> {
+        let grammar = self.grammar_mut();
+        let query = Query::new(grammar.ts_language, source)?;
+        let mut language_capture_ix = None;
+        let mut content_capture_ix = None;
+        for (ix, name) in query.capture_names().iter().enumerate() {
+            *match name.as_str() {
+                "language" => &mut language_capture_ix,
+                "content" => &mut content_capture_ix,
+                _ => continue,
+            } = Some(ix as u32);
+        }
+        let languages_by_pattern_ix = (0..query.pattern_count())
+            .map(|ix| {
+                query.property_settings(ix).iter().find_map(|setting| {
+                    if setting.key.as_ref() == "language" {
+                        return setting.value.clone();
+                    } else {
+                        None
+                    }
+                })
+            })
+            .collect();
+        if let Some(content_capture_ix) = content_capture_ix {
+            grammar.injection_config = Some(InjectionConfig {
+                query,
+                language_capture_ix,
+                content_capture_ix,
+                languages_by_pattern_ix,
+            });
+        }
+        Ok(self)
+    }
+
     fn grammar_mut(&mut self) -> &mut Grammar {
         Arc::get_mut(self.grammar.as_mut().unwrap()).unwrap()
     }
diff --git a/crates/language/src/syntax_map.rs b/crates/language/src/syntax_map.rs
new file mode 100644
index 0000000000..01ff0e50a1
--- /dev/null
+++ b/crates/language/src/syntax_map.rs
@@ -0,0 +1,418 @@
+use crate::{
+    Grammar, Language, LanguageRegistry, QueryCursorHandle, TextProvider, ToTreeSitterPoint,
+};
+use collections::VecDeque;
+use gpui::executor::Background;
+use std::{borrow::Cow, cell::RefCell, cmp::Ordering, ops::Range, sync::Arc};
+use sum_tree::{SeekTarget, SumTree};
+use text::{Anchor, BufferSnapshot, Point, Rope, ToOffset};
+use tree_sitter::{Parser, Tree};
+use util::post_inc;
+
+thread_local! {
+    static PARSER: RefCell<Parser> = RefCell::new(Parser::new());
+}
+
+#[derive(Default)]
+pub struct SyntaxMap {
+    next_layer_id: usize,
+    snapshot: SyntaxMapSnapshot,
+}
+
+#[derive(Clone, Default)]
+pub struct SyntaxMapSnapshot {
+    version: clock::Global,
+    layers: SumTree<SyntaxLayer>,
+}
+
+#[derive(Clone)]
+struct SyntaxLayer {
+    id: usize,
+    parent_id: Option<usize>,
+    range: SyntaxLayerRange,
+    tree: tree_sitter::Tree,
+    language: Arc<Language>,
+}
+
+#[derive(Debug, Clone)]
+struct SyntaxLayerSummary {
+    range: Range<Anchor>,
+    last_layer_range: Range<Anchor>,
+}
+
+#[derive(Clone, Debug)]
+struct SyntaxLayerRange(Range<Anchor>);
+
+impl SyntaxMap {
+    pub fn new(
+        executor: Arc<Background>,
+        registry: Arc<LanguageRegistry>,
+        language: Arc<Language>,
+        text: BufferSnapshot,
+        prev_set: Option<Self>,
+    ) -> Self {
+        let mut next_layer_id = 0;
+        let mut layers = Vec::new();
+        let mut injections = VecDeque::<(Option<usize>, _, Vec<tree_sitter::Range>)>::new();
+
+        injections.push_back((None, language, vec![]));
+        while let Some((parent_id, language, ranges)) = injections.pop_front() {
+            if let Some(grammar) = &language.grammar.as_deref() {
+                let id = post_inc(&mut next_layer_id);
+                let range = if let Some((first, last)) = ranges.first().zip(ranges.last()) {
+                    text.anchor_before(first.start_byte)..text.anchor_after(last.end_byte)
+                } else {
+                    Anchor::MIN..Anchor::MAX
+                };
+                let tree = Self::parse_text(grammar, text.as_rope(), None, ranges);
+                Self::get_injections(grammar, &text, &tree, id, &registry, &mut injections);
+                layers.push(SyntaxLayer {
+                    id,
+                    parent_id,
+                    range: SyntaxLayerRange(range),
+                    tree,
+                    language,
+                });
+            }
+        }
+
+        layers.sort_unstable_by(|a, b| SeekTarget::cmp(&a.range, &b.range, &text));
+
+        Self {
+            next_layer_id,
+            snapshot: SyntaxMapSnapshot {
+                layers: SumTree::from_iter(layers, &text),
+                version: text.version,
+            },
+        }
+    }
+
+    pub fn snapshot(&self) -> SyntaxMapSnapshot {
+        self.snapshot.clone()
+    }
+
+    fn interpolate(&mut self, text: &BufferSnapshot) {
+        let edits = text
+            .edits_since::<(Point, usize)>(&self.version)
+            .map(|edit| {
+                let (lines, bytes) = edit.flatten();
+                tree_sitter::InputEdit {
+                    start_byte: bytes.new.start,
+                    old_end_byte: bytes.new.start + bytes.old.len(),
+                    new_end_byte: bytes.new.end,
+                    start_position: lines.new.start.to_ts_point(),
+                    old_end_position: (lines.new.start + (lines.old.end - lines.old.start))
+                        .to_ts_point(),
+                    new_end_position: lines.new.end.to_ts_point(),
+                }
+            })
+            .collect::<Vec<_>>();
+        if edits.is_empty() {
+            return;
+        }
+    }
+
+    fn get_injections(
+        grammar: &Grammar,
+        text: &BufferSnapshot,
+        tree: &Tree,
+        id: usize,
+        registry: &Arc<LanguageRegistry>,
+        output: &mut VecDeque<(Option<usize>, Arc<Language>, Vec<tree_sitter::Range>)>,
+    ) {
+        let config = if let Some(config) = &grammar.injection_config {
+            config
+        } else {
+            return;
+        };
+
+        let mut query_cursor = QueryCursorHandle::new();
+        for mat in query_cursor.matches(
+            &config.query,
+            tree.root_node(),
+            TextProvider(text.as_rope()),
+        ) {
+            let content_ranges = mat
+                .nodes_for_capture_index(config.content_capture_ix)
+                .map(|node| node.range())
+                .collect::<Vec<_>>();
+            if content_ranges.is_empty() {
+                continue;
+            }
+            let language_name = config.languages_by_pattern_ix[mat.pattern_index]
+                .as_ref()
+                .map(|s| Cow::Borrowed(s.as_ref()))
+                .or_else(|| {
+                    let ix = config.language_capture_ix?;
+                    let node = mat.nodes_for_capture_index(ix).next()?;
+                    Some(Cow::Owned(text.text_for_range(node.byte_range()).collect()))
+                });
+            if let Some(language_name) = language_name {
+                if let Some(language) = registry.get_language(language_name.as_ref()) {
+                    output.push_back((Some(id), language, content_ranges))
+                }
+            }
+        }
+    }
+
+    fn parse_text(
+        grammar: &Grammar,
+        text: &Rope,
+        old_tree: Option<Tree>,
+        ranges: Vec<tree_sitter::Range>,
+    ) -> Tree {
+        PARSER.with(|parser| {
+            let mut parser = parser.borrow_mut();
+            let mut chunks = text.chunks_in_range(0..text.len());
+            parser
+                .set_included_ranges(&ranges)
+                .expect("overlapping ranges");
+            parser
+                .set_language(grammar.ts_language)
+                .expect("incompatible grammar");
+            parser
+                .parse_with(
+                    &mut move |offset, _| {
+                        chunks.seek(offset);
+                        chunks.next().unwrap_or("").as_bytes()
+                    },
+                    old_tree.as_ref(),
+                )
+                .expect("invalid language")
+        })
+    }
+}
+
+impl SyntaxMapSnapshot {
+    pub fn layers_for_range<'a, T: ToOffset>(
+        &self,
+        range: Range<T>,
+        buffer: &BufferSnapshot,
+    ) -> Vec<(Tree, &Grammar)> {
+        let start = buffer.anchor_before(range.start.to_offset(buffer));
+        let end = buffer.anchor_after(range.end.to_offset(buffer));
+
+        let mut cursor = self.layers.filter::<_, ()>(|summary| {
+            let is_before_start = summary.range.end.cmp(&start, buffer).is_lt();
+            let is_after_end = summary.range.start.cmp(&end, buffer).is_gt();
+            !is_before_start && !is_after_end
+        });
+
+        let mut result = Vec::new();
+        cursor.next(buffer);
+        while let Some(item) = cursor.item() {
+            if let Some(grammar) = &item.language.grammar {
+                result.push((item.tree.clone(), grammar.as_ref()));
+            }
+            cursor.next(buffer)
+        }
+
+        result
+    }
+}
+
+impl std::ops::Deref for SyntaxMap {
+    type Target = SyntaxMapSnapshot;
+
+    fn deref(&self) -> &Self::Target {
+        &self.snapshot
+    }
+}
+
+impl Default for SyntaxLayerSummary {
+    fn default() -> Self {
+        Self {
+            range: Anchor::MAX..Anchor::MIN,
+            last_layer_range: Anchor::MIN..Anchor::MAX,
+        }
+    }
+}
+
+impl sum_tree::Summary for SyntaxLayerSummary {
+    type Context = BufferSnapshot;
+
+    fn add_summary(&mut self, other: &Self, buffer: &Self::Context) {
+        if other.range.start.cmp(&self.range.start, buffer).is_lt() {
+            self.range.start = other.range.start;
+        }
+        if other.range.end.cmp(&self.range.end, buffer).is_gt() {
+            self.range.end = other.range.end;
+        }
+        self.last_layer_range = other.last_layer_range.clone();
+    }
+}
+
+impl Default for SyntaxLayerRange {
+    fn default() -> Self {
+        Self(Anchor::MIN..Anchor::MAX)
+    }
+}
+
+impl<'a> SeekTarget<'a, SyntaxLayerSummary, SyntaxLayerRange> for SyntaxLayerRange {
+    fn cmp(&self, cursor_location: &Self, buffer: &BufferSnapshot) -> Ordering {
+        self.0
+            .start
+            .cmp(&cursor_location.0.start, buffer)
+            .then_with(|| cursor_location.0.end.cmp(&self.0.end, buffer))
+    }
+}
+
+impl<'a> sum_tree::Dimension<'a, SyntaxLayerSummary> for SyntaxLayerRange {
+    fn add_summary(
+        &mut self,
+        summary: &'a SyntaxLayerSummary,
+        _: &<SyntaxLayerSummary as sum_tree::Summary>::Context,
+    ) {
+        self.0 = summary.last_layer_range.clone();
+    }
+}
+
+impl sum_tree::Item for SyntaxLayer {
+    type Summary = SyntaxLayerSummary;
+
+    fn summary(&self) -> Self::Summary {
+        SyntaxLayerSummary {
+            range: self.range.0.clone(),
+            last_layer_range: self.range.0.clone(),
+        }
+    }
+}
+
+impl std::fmt::Debug for SyntaxLayer {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("SyntaxLayer")
+            .field("id", &self.id)
+            .field("parent_id", &self.parent_id)
+            .field("range", &self.range)
+            .field("tree", &self.tree)
+            .finish()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::LanguageConfig;
+    use gpui::MutableAppContext;
+    use text::{Buffer, Point};
+    use unindent::Unindent as _;
+
+    #[gpui::test]
+    fn test_syntax_map(cx: &mut MutableAppContext) {
+        let buffer = Buffer::new(
+            0,
+            0,
+            r#"
+                fn a() {
+                    assert_eq!(
+                        b(vec![C {}]),
+                        vec![d.e],
+                    );
+                    println!("{}", f(|_| true));
+                }
+            "#
+            .unindent(),
+        );
+
+        let executor = cx.background().clone();
+        let registry = Arc::new(LanguageRegistry::test());
+        let language = Arc::new(rust_lang());
+        let snapshot = buffer.snapshot();
+        registry.add(language.clone());
+
+        let syntax_map = SyntaxMap::new(executor, registry, language, snapshot.clone(), None);
+
+        let layers = syntax_map.layers_for_range(Point::new(0, 0)..Point::new(0, 1), &snapshot);
+        assert_layers(
+            &layers,
+            &["(source_file (function_item name: (identifier)..."],
+        );
+
+        let layers = syntax_map.layers_for_range(Point::new(2, 0)..Point::new(2, 0), &snapshot);
+        assert_layers(
+            &layers,
+            &[
+                "...(function_item ... (block (expression_statement (macro_invocation...",
+                "...(tuple_expression (call_expression ... arguments: (arguments (macro_invocation...",
+            ],
+        );
+
+        let layers = syntax_map.layers_for_range(Point::new(2, 14)..Point::new(2, 16), &snapshot);
+        assert_layers(
+            &layers,
+            &[
+                "...(function_item ...",
+                "...(tuple_expression (call_expression ... arguments: (arguments (macro_invocation...",
+                "...(array_expression (struct_expression ...",
+            ],
+        );
+
+        let layers = syntax_map.layers_for_range(Point::new(3, 14)..Point::new(3, 16), &snapshot);
+        assert_layers(
+            &layers,
+            &[
+                "...(function_item ...",
+                "...(tuple_expression (call_expression ... arguments: (arguments (macro_invocation...",
+                "...(array_expression (field_expression ...",
+            ],
+        );
+
+        let layers = syntax_map.layers_for_range(Point::new(5, 12)..Point::new(5, 16), &snapshot);
+        assert_layers(
+            &layers,
+            &[
+                "...(function_item ...",
+                "...(call_expression ... (arguments (closure_expression ...",
+            ],
+        );
+    }
+
+    fn rust_lang() -> Language {
+        Language::new(
+            LanguageConfig {
+                name: "Rust".into(),
+                path_suffixes: vec!["rs".to_string()],
+                ..Default::default()
+            },
+            Some(tree_sitter_rust::language()),
+        )
+        .with_injection_query(
+            r#"
+                (macro_invocation
+                    (token_tree) @content
+                    (#set! "language" "rust"))
+            "#,
+        )
+        .unwrap()
+    }
+
+    fn assert_layers(layers: &[(Tree, &Grammar)], expected_layers: &[&str]) {
+        assert_eq!(
+            layers.len(),
+            expected_layers.len(),
+            "wrong number of layers"
+        );
+        for (i, (layer, expected_s_exp)) in layers.iter().zip(expected_layers.iter()).enumerate() {
+            let actual_s_exp = layer.0.root_node().to_sexp();
+            assert!(
+                string_contains_sequence(
+                    &actual_s_exp,
+                    &expected_s_exp.split("...").collect::<Vec<_>>()
+                ),
+                "layer {i}:\n\nexpected: {expected_s_exp}\nactual:   {actual_s_exp}",
+            );
+        }
+    }
+
+    pub fn string_contains_sequence(text: &str, parts: &[&str]) -> bool {
+        let mut last_part_end = 0;
+        for part in parts {
+            if let Some(start_ix) = text[last_part_end..].find(part) {
+                last_part_end = start_ix + part.len();
+            } else {
+                return false;
+            }
+        }
+        true
+    }
+}
diff --git a/crates/sum_tree/src/cursor.rs b/crates/sum_tree/src/cursor.rs
index 09f253d432..52200d64cf 100644
--- a/crates/sum_tree/src/cursor.rs
+++ b/crates/sum_tree/src/cursor.rs
@@ -608,9 +608,9 @@ where
 
 impl<'a, F, T, S, U> Iterator for FilterCursor<'a, F, T, U>
 where
-    F: Fn(&T::Summary) -> bool,
+    F: FnMut(&T::Summary) -> bool,
     T: Item<Summary = S>,
-    S: Summary<Context = ()>,
+    S: Summary<Context = ()>, //Context for the summary must be unit type, as .next() doesn't take arguments
     U: Dimension<'a, T::Summary>,
 {
     type Item = &'a T;
@@ -621,7 +621,7 @@ where
         }
 
         if let Some(item) = self.item() {
-            self.cursor.next_internal(&self.filter_node, &());
+            self.cursor.next_internal(&mut self.filter_node, &());
             Some(item)
         } else {
             None
diff --git a/crates/sum_tree/src/sum_tree.rs b/crates/sum_tree/src/sum_tree.rs
index fdfd5d9de2..cb05dff967 100644
--- a/crates/sum_tree/src/sum_tree.rs
+++ b/crates/sum_tree/src/sum_tree.rs
@@ -168,6 +168,8 @@ impl<T: Item> SumTree<T> {
         Cursor::new(self)
     }
 
+    /// Note: If the summary type requires a non `()` context, then the filter cursor
+    /// that is returned cannot be used with Rust's iterators.
     pub fn filter<'a, F, U>(&'a self, filter_node: F) -> FilterCursor<F, T, U>
     where
         F: FnMut(&T::Summary) -> bool,
diff --git a/crates/zed/src/languages.rs b/crates/zed/src/languages.rs
index 8dc20bdbd1..b7057bdd13 100644
--- a/crates/zed/src/languages.rs
+++ b/crates/zed/src/languages.rs
@@ -128,6 +128,11 @@ pub(crate) fn language(
             .with_outline_query(query.as_ref())
             .expect("failed to load outline query");
     }
+    if let Some(query) = load_query(name, "/injections") {
+        language = language
+            .with_injection_query(query.as_ref())
+            .expect("failed to load injection query");
+    }
     if let Some(lsp_adapter) = lsp_adapter {
         language = language.with_lsp_adapter(lsp_adapter)
     }
diff --git a/crates/zed/src/languages/rust/injections.scm b/crates/zed/src/languages/rust/injections.scm
new file mode 100644
index 0000000000..9d8c03c889
--- /dev/null
+++ b/crates/zed/src/languages/rust/injections.scm
@@ -0,0 +1,3 @@
+(macro_invocation
+  (token_tree) @content)
+  (#set! "language" "rust"))
\ No newline at end of file