diff --git a/crates/ide-language/src/registry.rs b/crates/ide-language/src/registry.rs
index 85aa1ffad..10ab386e0 100644
--- a/crates/ide-language/src/registry.rs
+++ b/crates/ide-language/src/registry.rs
@@ -8,6 +8,7 @@ use std::sync::Arc;
 
 /// Built-in definitions, embedded at compile time. Add new languages here.
 const BUILTIN: &[(&str, &str)] = &[
+    ("bat", include_str!("../../../languages/bat.toml")),
     ("c", include_str!("../../../languages/c.toml")),
     ("clojure", include_str!("../../../languages/clojure.toml")),
     ("cmake", include_str!("../../../languages/cmake.toml")),
@@ -348,8 +349,10 @@ mod tests {
     use super::*;
     use std::collections::{HashMap, HashSet};
 
-    /// `name`s exported by `@codemirror/language-data` (the UI resolves `ui-mode` against these).
+    /// `name`s exported by `@codemirror/language-data` or built into `src/editor/core/cm/languages.ts`
+    /// (the UI resolves `ui-mode` against these).
     const UI_MODES: &[&str] = &[
+        "Batch",
         "C",
         "C++",
         "CQL",
@@ -511,6 +514,7 @@ mod tests {
         assert_eq!(reg.detect(Path::new("script"), Some("#!/usr/bin/env python3")).as_str(), "python");
         assert_eq!(detect(&reg, "README"), "plaintext");
         assert_eq!(detect(&reg, "unknown.zzz"), "plaintext");
+        assert_eq!(reg.get(&LanguageId::new("bat")).unwrap().line_comment.as_deref(), Some("@REM"));
         let rust = reg.get(&LanguageId::new("rust")).unwrap();
         assert_eq!(rust.language_servers[0].name, "rust-analyzer");
     }
@@ -679,6 +683,8 @@ mod tests {
             ("deploy.sh", "shellscript"),
             (".zshrc", "shellscript"),
             ("Build.ps1", "powershell"),
+            ("build.bat", "bat"),
+            ("run.cmd", "bat"),
             ("schema.sql", "sql"),
             ("api.http", "http"),
             ("api.rest", "http"),
diff --git a/languages/bat.toml b/languages/bat.toml
new file mode 100644
index 000000000..5ce36ca33
--- /dev/null
+++ b/languages/bat.toml
@@ -0,0 +1,6 @@
+id = "bat"
+name = "Batch"
+extensions = ["bat", "cmd"]
+line-comment = "@REM"
+indent = { tab-size = 4, insert-spaces = true }
+ui-mode = "Batch"
diff --git a/src/editor/core/backend.ts b/src/editor/core/backend.ts
index c93be8dd6..05d53647f 100644
--- a/src/editor/core/backend.ts
+++ b/src/editor/core/backend.ts
@@ -115,6 +115,8 @@ const EXT_LANG: Record<string, string> = {
   cpp: "cpp",
   h: "c",
   sh: "shellscript",
+  bat: "bat",
+  cmd: "bat",
   sql: "sql",
   xml: "xml",
 };
@@ -219,6 +221,15 @@ const MEM_LANGUAGES: LanguageInfo[] = [
     blockComment: null,
     indent: { tabSize: 2, insertSpaces: true },
   },
+  {
+    id: "bat",
+    name: "Batch",
+    extensions: ["bat", "cmd"],
+    uiMode: "Batch",
+    lineComment: "@REM",
+    blockComment: null,
+    indent: { tabSize: 4, insertSpaces: true },
+  },
   {
     id: "plaintext",
     name: "Plain Text",
diff --git a/src/editor/core/cm/comments.ts b/src/editor/core/cm/comments.ts
index fe22cc108..4509a61f2 100644
--- a/src/editor/core/cm/comments.ts
+++ b/src/editor/core/cm/comments.ts
@@ -96,13 +96,15 @@ export const commentLine: Command = (view) => {
   const changes: ChangeSpec[] = [];
   blocks.forEach((b, bi) => {
     const token = tokens[bi]!;
+    // A word token (Batch `@REM`) needs a separator even when comment spacing is off.
+    const addSpace = style.addSpace || /\w$/.test(token);
     if (allCommented) {
       for (let n = b.startLine; n <= b.endLine; n++) {
         const line = doc.line(n);
         const start = line.from + leadingWs(line.text);
         if (!doc.sliceString(start, line.to).startsWith(token) || !line.text.trim()) continue;
         let end = start + token.length;
-        if (style.addSpace && doc.sliceString(end, end + 1) === " ") end++;
+        if (addSpace && doc.sliceString(end, end + 1) === " ") end++;
         // Nothing but whitespace left: the line is emptied.
         if (!doc.sliceString(end, line.to).trim()) changes.push({ from: line.from, to: line.to });
         else changes.push({ from: start, to: end });
@@ -111,7 +113,7 @@ export const commentLine: Command = (view) => {
     }
     const commentStart = b.caretUpdate === "commentStart";
     const prefixFor = (shifted: number, line: { to: number }) =>
-      token + (style.addSpace && (shifted < line.to || (commentStart && shifted < doc.length)) ? " " : "");
+      token + (addSpace && (shifted < line.to || (commentStart && shifted < doc.length)) ? " " : "");
     if (style.atFirstColumn) {
       for (let n = b.startLine; n <= b.endLine; n++) {
         const line = doc.line(n);
diff --git a/src/editor/core/cm/editing.test.ts b/src/editor/core/cm/editing.test.ts
index 3be938f42..326134312 100644
--- a/src/editor/core/cm/editing.test.ts
+++ b/src/editor/core/cm/editing.test.ts
@@ -2,7 +2,7 @@ import { afterEach, describe, expect, it } from "vitest";
 import { EditorSelection, EditorState, type Extension } from "@codemirror/state";
 import { EditorView } from "@codemirror/view";
 import { insertNewlineAndIndent } from "@codemirror/commands";
-import { indentService, indentUnit } from "@codemirror/language";
+import { indentService, indentUnit, ensureSyntaxTree } from "@codemirror/language";
 import {
   addCaretsToLineEnds,
   commentLine,
@@ -13,7 +13,7 @@ import {
   toggleCase,
   unselectOccurrence,
 } from "./editing";
-import { commentTokens } from "./languages";
+import { batchLanguage, commentTokens, findLanguageDescription } from "./languages";
 import { toggleCaret } from "./multiCaret";
 import { enterInLineComment, lineCommentStyle } from "./comments";
 import { languages } from "@codemirror/language-data";
@@ -338,3 +338,51 @@ describe("fallback indentation boundaries", () => {
     expect(show(v)).toBe(expected);
   });
 });
+
+describe("Batch language mode and @REM comment toggle", () => {
+  it("resolves Batch by uiMode and .bat / .cmd extensions and toggles @REM comments", () => {
+    expect(findLanguageDescription("Batch", "build.bat")?.name).toBe("Batch");
+    expect(findLanguageDescription(null, "deploy.cmd")?.name).toBe("Batch");
+    const v = make("echo| hello\n", batchLanguage);
+    commentLine(v);
+    expect(v.state.doc.toString()).toBe("@REM echo hello\n");
+    v.dispatch({ selection: EditorSelection.cursor(0) });
+    commentLine(v);
+    expect(v.state.doc.toString()).toBe("echo hello\n");
+  });
+
+  it("highlights keywords, labels, variables, strings and :: / REM comments", () => {
+    const src = [
+      ":: header comment",
+      "@REM line comment",
+      "@echo off",
+      "setlocal",
+      'set "APP=demo"',
+      "for %%i in (a b) do if exist %APP% call :sub !COUNT!",
+      ":sub",
+      "rem note",
+      "exit /b 0",
+      "endlocal",
+    ].join("\n");
+    const state = EditorState.create({ doc: src, extensions: batchLanguage });
+    const tree = ensureSyntaxTree(state, state.doc.length, 5000)!;
+    const tokens: Array<[string, string]> = [];
+    tree.iterate({
+      enter: (n) => {
+        if (n.name !== "Document" && n.from < n.to) tokens.push([n.name, state.sliceDoc(n.from, n.to)]);
+      },
+    });
+    const has = (tag: string, text: string) => tokens.some(([n, s]) => n.includes(tag) && s === text);
+    expect(has("comment", ":: header comment")).toBe(true);
+    expect(has("comment", "@REM line comment")).toBe(true);
+    expect(has("comment", "rem note")).toBe(true);
+    for (const kw of ["echo", "setlocal", "set", "for", "in", "do", "if", "exist", "call", "exit", "endlocal"]) {
+      expect(has("keyword", kw)).toBe(true);
+    }
+    expect(has("string", '"APP=demo"')).toBe(true);
+    expect(has("variableName", "%%i")).toBe(true);
+    expect(has("variableName", "%APP%")).toBe(true);
+    expect(has("variableName", "!COUNT!")).toBe(true);
+    expect(has("labelName", ":sub")).toBe(true);
+  });
+});
diff --git a/src/editor/core/cm/editing.ts b/src/editor/core/cm/editing.ts
index 69594bc4f..f7fc7311a 100644
--- a/src/editor/core/cm/editing.ts
+++ b/src/editor/core/cm/editing.ts
@@ -560,6 +560,7 @@ export const KEYWORD_BLOCK_LANGS = new Set([
   "r",
   "perl",
   "powershell",
+  "bat",
 ]);
 /** A line opening an indented body in `end` / layout languages (Ruby, Lua, Elixir, Haskell…). */
 const KEYWORD_HEAD =
diff --git a/src/editor/core/cm/languages.ts b/src/editor/core/cm/languages.ts
index 7dc310fcf..07ac1b3af 100644
--- a/src/editor/core/cm/languages.ts
+++ b/src/editor/core/cm/languages.ts
@@ -9,8 +9,10 @@ import {
   LRLanguage,
   LanguageDescription,
   LanguageSupport,
+  StreamLanguage,
   indentService,
   language as languageFacet,
+  type StreamParser,
 } from "@codemirror/language";
 import { styleTags, tags as t } from "@lezer/highlight";
 import { languages as languageData } from "@codemirror/language-data";
@@ -58,18 +60,90 @@ export function uiModeForPath(path: string): string | null | undefined {
 
 const supports = new Map<string, Promise<LanguageSupport | null>>();
 
+const BATCH_KEYWORDS = new Set([
+  "echo",
+  "set",
+  "if",
+  "else",
+  "goto",
+  "call",
+  "for",
+  "in",
+  "do",
+  "exit",
+  "setlocal",
+  "endlocal",
+  "not",
+  "exist",
+  "defined",
+  "errorlevel",
+  "shift",
+  "pushd",
+  "popd",
+  "cd",
+  "start",
+  "pause",
+  "title",
+  "cls",
+]);
+
+const batchParser: StreamParser<null> = {
+  name: "bat",
+  startState: () => null,
+  token(stream) {
+    if (stream.eatSpace()) return null;
+    const lineStart = /^\s*$/.test(stream.string.slice(0, stream.start));
+    if (lineStart) {
+      if (stream.match(/^@?::.*$/)) return "comment";
+      if (stream.match(/^@?rem(?:\s.*|$)/i)) return "comment";
+      if (stream.match(/^:[A-Za-z0-9_.-]+/)) return "labelName";
+    }
+    if (stream.match(/^::.*$/)) return "comment";
+    if (stream.match(/^"(?:[^"]|"")*(?:"|$)/)) return "string";
+    if (
+      stream.match(/^%%(?:~[a-zA-Z]*)?[a-zA-Z0-9_]|^%[^%\s]+%|^%(?:~[a-zA-Z]*[0-9]|\*|[0-9])|^![A-Za-z_][A-Za-z0-9_]*!/)
+    )
+      return "variableName";
+    if ((lineStart || /\s/.test(stream.string[stream.start - 1]!)) && stream.match(/^:[A-Za-z0-9_.-]+/))
+      return "labelName";
+    if (stream.eat("@")) return "punctuation";
+    if (stream.match(/^\d+\b/)) return "number";
+    const word =
+      (stream.start === 0 || !/[A-Za-z0-9_.]/.test(stream.string[stream.start - 1]!)) &&
+      stream.match(/^[A-Za-z_][A-Za-z0-9_]*/);
+    if (word) {
+      const lower = (typeof word === "object" ? word[0] : "").toLowerCase();
+      return BATCH_KEYWORDS.has(lower) ? "keyword" : null;
+    }
+    stream.next();
+    return null;
+  },
+  languageData: { commentTokens: { line: "@REM" } },
+};
+
+export const batchLanguage = StreamLanguage.define(batchParser);
+
+const batchLanguageDescription = LanguageDescription.of({
+  name: "Batch",
+  alias: ["bat", "cmd"],
+  extensions: ["bat", "cmd"],
+  support: new LanguageSupport(batchLanguage),
+});
+
+const BUILTIN_MODES: readonly LanguageDescription[] = [...languageData, batchLanguageDescription];
+
 export function findLanguageDescription(uiMode: string | null, path: string): LanguageDescription | null {
   if (uiMode) {
     const contributed = _languageMode(uiMode);
     if (contributed) return contributed;
-    const exact = languageData.find((l) => l.name === uiMode);
+    const exact = BUILTIN_MODES.find((l) => l.name === uiMode);
     if (exact) return exact;
-    const loose = LanguageDescription.matchLanguageName(languageData, uiMode, false);
+    const loose = LanguageDescription.matchLanguageName(BUILTIN_MODES, uiMode, false);
     if (loose) return loose;
   }
   return uiMode === null && infos
     ? null
-    : LanguageDescription.matchFilename(languageData, path.slice(path.lastIndexOf("/") + 1));
+    : LanguageDescription.matchFilename(BUILTIN_MODES, path.slice(path.lastIndexOf("/") + 1));
 }
 
 /** Loads (once) the CodeMirror language for `desc`. */
diff --git a/src/features/run/configs.test.ts b/src/features/run/configs.test.ts
index 81026a41b..0f61d66c2 100644
--- a/src/features/run/configs.test.ts
+++ b/src/features/run/configs.test.ts
@@ -163,6 +163,9 @@ describe("context configuration", () => {
     expect(fileRole("src/main.rs")).toBe("main");
     expect(fileRole("cmd/main.go", "package main\nfunc main() {}")).toBe("main");
     expect(fileRole("tools/gen.py")).toBe("script");
+    expect(fileRole("scripts/build.bat", undefined, true)).toBe("script");
+    expect(fileRole("scripts/run.cmd", undefined, true)).toBe("script");
+    expect(fileRole("scripts/build.bat", undefined, false)).toBeNull();
     expect(fileRole("README.md")).toBeNull();
   });
 
@@ -196,6 +199,17 @@ describe("context configuration", () => {
       args: ["tools/gen.py"],
     });
     expect(contextConfig("scripts/build.sh", configs)).toMatchObject({ command: "sh", args: ["scripts/build.sh"] });
+    expect(contextConfig("scripts/build.bat", configs, undefined, true)).toMatchObject({
+      command: "cmd.exe",
+      args: ["/c", "build.bat"],
+      cwd: "scripts",
+    });
+    expect(contextConfig("run.cmd", configs, undefined, true)).toMatchObject({
+      command: "cmd.exe",
+      args: ["/c", "run.cmd"],
+      cwd: null,
+    });
+    expect(contextConfig("scripts/build.bat", configs, undefined, false)).toBeNull();
     expect(contextConfig("docs/readme.md", configs)).toBeNull();
   });
 
diff --git a/src/features/run/context.ts b/src/features/run/context.ts
index c7969b1a4..82f849cc2 100644
--- a/src/features/run/context.ts
+++ b/src/features/run/context.ts
@@ -4,10 +4,11 @@
  * direct interpreter invocation for main files. Best effort, IDEA-style.
  */
 import type { RunConfig } from "@/platform/ipc";
+import { isWindows } from "./jvmTypes";
 
 export type FileRole = "test" | "main" | "script" | null;
 
-export function fileRole(relPath: string, content?: string): FileRole {
+export function fileRole(relPath: string, content?: string, windows = isWindows()): FileRole {
   const name = relPath.split("/").pop() ?? relPath;
   if (
     /\.(test|spec)\.[cm]?[jt]sx?$/.test(name) ||
@@ -23,6 +24,7 @@ export function fileRole(relPath: string, content?: string): FileRole {
   if (/\.(kt|java)$/.test(name) && content !== undefined && /\bfun\s+main\s*\(|static\s+void\s+main\s*\(/.test(content))
     return "main";
   if (/\.(py|sh|bash|zsh|[cm]?js|ts)$/.test(name)) return "script";
+  if (windows && /\.(bat|cmd)$/i.test(name)) return "script";
   return null;
 }
 
@@ -194,7 +196,7 @@ function mainConfigFor(relPath: string, configs: RunConfig[]): RunConfig | null
   return null;
 }
 
-function scriptConfigFor(relPath: string, configs: RunConfig[]): RunConfig | null {
+function scriptConfigFor(relPath: string, configs: RunConfig[], windows = isWindows()): RunConfig | null {
   const base: RunConfig = {
     id: `context:file:${relPath}`,
     name: relPath.split("/").pop() ?? relPath,
@@ -220,14 +222,23 @@ function scriptConfigFor(relPath: string, configs: RunConfig[]): RunConfig | nul
     const shell = relPath.endsWith(".zsh") ? "zsh" : relPath.endsWith(".bash") ? "bash" : "sh";
     return { ...base, command: shell, args: [relPath] };
   }
+  if (windows && /\.(bat|cmd)$/i.test(relPath)) {
+    const file = relPath.split("/").pop() ?? relPath;
+    return { ...base, command: "cmd.exe", args: ["/c", file], cwd: dirOf(relPath) || null };
+  }
   return null;
 }
 
 /** Config to run for the file at `relPath` (relative to the project root), if any. */
-export function contextConfig(relPath: string, configs: RunConfig[], content?: string): RunConfig | null {
-  const role = fileRole(relPath, content);
+export function contextConfig(
+  relPath: string,
+  configs: RunConfig[],
+  content?: string,
+  windows = isWindows(),
+): RunConfig | null {
+  const role = fileRole(relPath, content, windows);
   if (role === "test") return testConfigFor(relPath, configs);
-  if (role === "main") return mainConfigFor(relPath, configs) ?? scriptConfigFor(relPath, configs);
-  if (role === "script") return scriptConfigFor(relPath, configs);
+  if (role === "main") return mainConfigFor(relPath, configs) ?? scriptConfigFor(relPath, configs, windows);
+  if (role === "script") return scriptConfigFor(relPath, configs, windows);
   return null;
 }
diff --git a/src/features/run/producers.test.ts b/src/features/run/producers.test.ts
index 5782b9060..d9ee794d1 100644
--- a/src/features/run/producers.test.ts
+++ b/src/features/run/producers.test.ts
@@ -173,6 +173,17 @@ describe("single-file producers (scratches)", () => {
       "js-debug",
     );
     expect(run(scratch("tool", "#!/usr/bin/env python3\n"))).toMatchObject({ command: "/bin/python3", args: ["tool"] });
+    expect(run(scratch("build.bat"), { ...ALL, windows: true })).toMatchObject({
+      command: "cmd.exe",
+      args: ["/c", "build.bat"],
+      cwd: SCRATCH,
+    });
+    expect(run({ path: `${ROOT}/scripts/run.cmd`, root: ROOT, configs: [] }, { ...ALL, windows: true })).toMatchObject({
+      command: "cmd.exe",
+      args: ["/c", "run.cmd"],
+      cwd: "scripts",
+    });
+    expect(produceContext(scratch("build.bat"), ALL)).toBeNull();
     expect(produceContext(scratch("notes", "just text"), ALL)).toBeNull();
     expect(shebang("#!/usr/bin/env node")).toEqual(["node"]);
   });
diff --git a/src/features/run/producers.ts b/src/features/run/producers.ts
index 117cca4b0..184cd6729 100644
--- a/src/features/run/producers.ts
+++ b/src/features/run/producers.ts
@@ -15,6 +15,7 @@ import { currentRoots } from "@/platform/projectRoots";
 import { applicationConfig, jvmModuleDir } from "./application";
 import { formatArgs } from "./configs";
 import { contextConfig, fileRole, projectPython, testBasesFor, testConfigFor } from "./context";
+import { isWindows } from "./jvmTypes";
 import { detectRunTargets, targetConfig, targetLanguage, type RunTarget } from "./targets";
 import { tx } from "@/platform/i18n";
 
@@ -154,6 +155,7 @@ export type ScriptLanguage =
   | "ts"
   | "python"
   | "shell"
+  | "bat"
   | "ruby"
   | "php"
   | "perl"
@@ -192,6 +194,7 @@ export function scriptLanguage(path: string, content?: string): ScriptLanguage |
   if (/\.[cm]?ts$/.test(name) && !/\.d\.[cm]?ts$/.test(name)) return "ts";
   if (/\.pyw?$/.test(name)) return "python";
   if (/\.(sh|bash|zsh)$/.test(name)) return "shell";
+  if (/\.(bat|cmd)$/i.test(name)) return "bat";
   if (/\.rb$/.test(name)) return "ruby";
   if (/\.php$/.test(name)) return "php";
   if (/\.pl$/.test(name)) return "perl";
@@ -229,6 +232,8 @@ export function toolsFor(lang: ScriptLanguage, content?: string): string[] {
         (n, i, all) => all.indexOf(n) === i,
       );
     }
+    case "bat":
+      return [];
     case "ruby":
       return ["ruby"];
     case "php":
@@ -669,6 +674,14 @@ export function produceFile(input: ContextInput, env: ToolEnv): Produced | null
         config: fileConfig(s, "shell", t.command, [...(sb?.slice(1) ?? []), s.arg]),
       };
     }
+    case "bat": {
+      if (!(env.windows ?? isWindows())) return null;
+      return {
+        name: s.file,
+        scope: "file",
+        config: { ...fileConfig(s, "shell", "cmd.exe", ["/c", s.file]), cwd: dirName(s.idPath) || null },
+      };
+    }
     case "ruby":
     case "php":
     case "perl":
diff --git a/src/ui/icons.test.tsx b/src/ui/icons.test.tsx
index f2a97d747..72611ce46 100644
--- a/src/ui/icons.test.tsx
+++ b/src/ui/icons.test.tsx
@@ -181,6 +181,8 @@ describe("fileIconName", () => {
     [".envrc", "file-shell"],
     ["run.sh", "file-shell"],
     ["build.ps1", "file-powershell"],
+    ["build.bat", "file-windows"],
+    ["run.cmd", "file-windows"],
     ["server.log", "file-log"],
     ["paper.tex", "file-latex"],
     ["photo.PNG", "file-image"],