diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 2be1d545..eb40d470 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -19,7 +19,7 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
-      - name: npm install
-        run: npm install
+      - name: Compile
+        run: npm install && npm run build
       - name: Run the linter
         run: ./lint
diff --git a/.gitignore b/.gitignore
index e2822c74..165f3da1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 # Ignore hidden Mac OS directory files
 **/.DS_Store
 node_modules/
+support/dist/
diff --git a/.prettierignore b/.prettierignore
index 178135c2..fefc105e 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -1 +1 @@
-/dist/
+/support/dist/
diff --git a/.vscode/tasks.json b/.vscode/tasks.json
new file mode 100644
index 00000000..ed6e5d3e
--- /dev/null
+++ b/.vscode/tasks.json
@@ -0,0 +1,99 @@
+{
+  // See https://go.microsoft.com/fwlink/?LinkId=733558
+  // for the documentation about the tasks.json format
+  "version": "2.0.0",
+  "tasks": [
+    {
+      "label": "./lint",
+      "detail": "Runs all supplied linters. This is the same check that runs on all pull requests.",
+      "type": "npm",
+      "script": "lint",
+      "problemMatcher": {
+        "fileLocation": ["relative", "${workspaceFolder}"],
+        "severity": "error",
+        "owner": "lint-owner",
+        "source": "lint-source",
+        "pattern": {
+          "regexp": "^(.*?):(\\d+)(?::(\\d+))? ((?:MD|VL)\\S+) (.*)$",
+          "file": 1,
+          "line": 2,
+          "column": 3,
+          "code": 4,
+          "message": 5
+        }
+      }
+    },
+    {
+      "label": "./lint (watch)",
+      "detail": "Runs all linters. This is the same check that runs on all pull requests.",
+      "type": "npm",
+      "script": "lint:watch",
+      "isBackground": true,
+      "problemMatcher": {
+        "fileLocation": ["relative", "${workspaceFolder}"],
+        "severity": "error",
+        "owner": "lint-owner",
+        "source": "lint-source",
+        "pattern": {
+          "regexp": "^(.*?):(\\d+)(?::(\\d+))? ((?:MD|VL)\\S+) (.*)$",
+          "file": 1,
+          "line": 2,
+          "column": 3,
+          "code": 4,
+          "message": 5
+        },
+        "background": {
+          "activeOnStart": true,
+          "beginsPattern": "^lint: RUN$",
+          "endsPattern": "^lint: (PASS|FAIL)$"
+        }
+      }
+    },
+    {
+      "label": "./lint validate-links",
+      "detail": "Check markdown for broken internal links & images",
+      "type": "npm",
+      "script": "lint:validate-links",
+      "problemMatcher": {
+        "fileLocation": ["relative", "${workspaceFolder}"],
+        "severity": "error",
+        "owner": "lint-owner",
+        "source": "lint-source",
+        "pattern": {
+          "regexp": "^(.*?):(\\d+)(?::(\\d+))? ((?:MD|VL)\\S+) (.*)$",
+          "file": 1,
+          "line": 2,
+          "column": 3,
+          "code": 4,
+          "message": 5
+        }
+      }
+    },
+    {
+      "label": "./lint validate-links (watch)",
+      "detail": "Check markdown for broken internal links & images",
+      "type": "npm",
+      "script": "lint:validate-links:watch",
+      "isBackground": true,
+      "problemMatcher": {
+        "fileLocation": ["relative", "${workspaceFolder}"],
+        "severity": "error",
+        "owner": "lint-owner",
+        "source": "lint-source",
+        "pattern": {
+          "regexp": "^(.*?):(\\d+)(?::(\\d+))? ((?:MD|VL)\\S+) (.*)$",
+          "file": 1,
+          "line": 2,
+          "column": 3,
+          "code": 4,
+          "message": 5
+        },
+        "background": {
+          "activeOnStart": true,
+          "beginsPattern": "^validate-links: RUN$",
+          "endsPattern": "^validate-links: (PASS|FAIL)$"
+        }
+      }
+    }
+  ]
+}
diff --git a/dist/parse.js b/dist/parse.js
deleted file mode 100644
index bfeee3d8..00000000
--- a/dist/parse.js
+++ /dev/null
@@ -1,35 +0,0 @@
-import mit from "markdown-it";
-export const parse = (content) => {
-    const parser = mit();
-    const tokens = parser.parse(content, {});
-    const parsedLinks = [];
-    const parsedImages = [];
-    const scan = (tokens) => {
-        tokens.forEach((token, index) => {
-            if (token.type === "link_open") {
-                const indexOfNextClose = tokens.findIndex((t2, i2) => i2 > index && t2.type === "link_close");
-                if (indexOfNextClose > index) {
-                    parsedLinks.push({
-                        target: token.attrGet("href"),
-                        content: tokens
-                            .slice(index + 1, indexOfNextClose)
-                            .map((t) => t.content)
-                            .join(""),
-                    });
-                }
-            }
-            if (token.type === "image")
-                parsedImages.push({
-                    src: token.attrGet("src"),
-                    alt: token.content,
-                });
-            if (token.children)
-                scan(token.children);
-        });
-    };
-    scan(tokens);
-    return {
-        links: parsedLinks,
-        images: parsedImages,
-    };
-};
diff --git a/dist/validateLinks.js b/dist/validateLinks.js
deleted file mode 100644
index 018c7ea7..00000000
--- a/dist/validateLinks.js
+++ /dev/null
@@ -1,80 +0,0 @@
-import { exec } from "node:child_process";
-import { readFile } from "node:fs/promises";
-import { parse } from "./parse.js";
-import path, { dirname, normalize } from "node:path/posix";
-import { isAbsolute } from "node:path";
-const findAllFilesInGit = async () => {
-    return await new Promise((resolve, reject) => {
-        exec("git ls-files -z", (error, stdout, stderr) => {
-            if (error)
-                reject(error);
-            if (stderr)
-                reject(new Error(`git ls-files outputted on stderr: ${stderr}`));
-            else
-                resolve(stdout.split("\0").filter(Boolean));
-        });
-    });
-};
-const findMarkdownFiles = (files) => {
-    const ignorePattern = /^(README|LICENSE|contributing\/)/;
-    return files.filter((f) => f.toLocaleLowerCase().endsWith(".md") && !ignorePattern.test(f));
-};
-const scanForLinks = async (filenames) => {
-    return Promise.all(filenames.map(async (filename) => {
-        const content = await readFile(filename, "utf-8");
-        return { filename, ...parse(content) };
-    }));
-};
-const externalLinkPattern = /^\w+:/;
-const isExternalLink = (t) => externalLinkPattern.test(t);
-const main = async () => {
-    const gitFiles = await findAllFilesInGit();
-    // For now, we assume that there are no case clashes
-    const lowercaseGitFiles = gitFiles.map((s) => s.toLocaleLowerCase());
-    const markdownFilenames = findMarkdownFiles(gitFiles);
-    const parsedFiles = await scanForLinks(markdownFilenames);
-    let errors = 0;
-    for (const parsedFile of parsedFiles) {
-        for (const img of parsedFile.images) {
-            if (!isExternalLink(img.src)) {
-                const resolved = path.join(dirname(parsedFile.filename), img.src);
-                const exists = lowercaseGitFiles.includes(resolved.toLocaleLowerCase());
-                if (!exists) {
-                    console.log(`error BROKEN-INTERNAL-IMAGE ${parsedFile.filename}:0 Broken internal image reference ${img.src}`);
-                    ++errors;
-                }
-            }
-        }
-        for (const link of parsedFile.links) {
-            if (link.target.startsWith("#")) {
-                // Already checked by the linter
-                continue;
-            }
-            if (!isExternalLink(link.target)) {
-                const target = link.target.split("#")[0];
-                let resolved;
-                if (isAbsolute(target)) {
-                    resolved = normalize(`./${target}`);
-                }
-                else {
-                    resolved = normalize(path.join(dirname(parsedFile.filename), target));
-                }
-                const isFile = lowercaseGitFiles.includes(resolved.toLocaleLowerCase());
-                const resolvedWithTrailingSlash = resolved.endsWith("/")
-                    ? resolved.toLocaleLowerCase()
-                    : `${resolved.toLocaleLowerCase()}/`;
-                const isDirectory = lowercaseGitFiles.some((s) => s.startsWith(resolvedWithTrailingSlash));
-                if (!isFile && !isDirectory) {
-                    console.log(`error BROKEN-INTERNAL-LINK ${parsedFile.filename}:0 Link target does not exist: ${target}`);
-                    ++errors;
-                }
-            }
-        }
-    }
-    if (errors > 0)
-        process.exit(1);
-};
-main().catch((error) => {
-    console.error(error);
-    process.exit(1);
-});
diff --git a/lint b/lint
index e0dae5d8..e031146b 100755
--- a/lint
+++ b/lint
@@ -2,41 +2,58 @@
 
 set -eu
 
-if [ "${1:-}" == "--fix" ] ; then
-  npm exec -- markdownlint --ignore 'node_modules/' --fix '**/*.md'
-  npm exec -- prettier --write .
-else
-  trap '
-    if [ $? -ne 0 ] ; then
-      echo "Try '\''./lint --fix'\'' to see if any automatic fixes are possible"
+validate-links() {
+    echo "validate-links: RUN"
+    if npm exec -- node support/dist/validateLinks.js ; then
+      echo validate-links: PASS
+    else
+      echo validate-links: FAIL
+      return 1
     fi
-  ' 0
+}
 
-  rc=0
-
-  echo "validateLinks: ..."
-  if npm exec -- node dist/validateLinks.js ; then
-    echo validateLinks: PASS
-  else
-    echo validateLinks: FAIL
-    rc=1
-  fi
-
-  echo "markdownlint: ..."
+markdownlint() {
+  echo "markdownlint: RUN"
   if npm exec -- markdownlint --ignore 'node_modules/' '**/*.md' ; then
     echo "markdownlint: PASS"
   else
     echo "markdownlint: FAIL"
-    rc=1
+    return 1
   fi
+}
 
-  echo "prettier: ..."
+prettier() {
+  echo "prettier: RUN"
   if npm exec -- prettier --check . ; then
     echo "prettier: PASS"
   else
     echo "prettier: FAIL"
-    rc=1
+    return 1
   fi
+}
+
+all() {
+  local rc=0
+  echo "lint: RUN"
+  validate-links || rc=1
+  markdownlint || rc=1
+  prettier || rc=1
 
-  exit $rc
+  if [ $rc -eq 0 ] ; then
+    echo "lint: PASS"
+  else
+    echo "lint: FAIL"
+    echo "Try './lint --fix' to see if any automatic fixes are possible"
+  fi
+
+  return $rc
+}
+
+if [ "${1:-}" == "--fix" ] ; then
+  npm exec -- markdownlint --ignore 'node_modules/' --fix '**/*.md' || :
+  npm exec -- prettier --write . || :
+elif [ "${1:-}" == "validate-links" ] ; then
+  validate-links
+else
+  all
 fi
diff --git a/package.json b/package.json
index 63d700b5..2e19c8d5 100644
--- a/package.json
+++ b/package.json
@@ -8,5 +8,13 @@
     "@types/markdown-it": "^14.1.2",
     "@types/node": "^22.14.1",
     "typescript": "^5.8.3"
+  },
+  "scripts": {
+    "build": "tsc -p support/tsconfig.json",
+    "lint": "./lint",
+    "lint:fix": "./lint --fix",
+    "lint:validate-links": "./lint validate-links",
+    "lint:validate-links:watch": "node support/dist/watch.js ./lint validate-links",
+    "lint:watch": "node support/dist/watch.js ./lint"
   }
 }
diff --git a/parse.ts b/support/src/parse.ts
similarity index 71%
rename from parse.ts
rename to support/src/parse.ts
index 1857dc61..39fb75fc 100644
--- a/parse.ts
+++ b/support/src/parse.ts
@@ -1,14 +1,17 @@
 import mit from "markdown-it";
 import type { Token } from "markdown-it/index.js";
+import { sourceLocationOf, type SourceLocation } from "./sourceLocation.js";
 
 export type ParsedLink = {
   readonly target: string;
   readonly content: string;
+  readonly sourceLocation: SourceLocation | null;
 };
 
 export type ParsedImage = {
   readonly src: string;
   readonly alt: string;
+  readonly sourceLocation: SourceLocation | null;
 };
 
 export type ParseResult = {
@@ -31,21 +34,26 @@ export const parse = (content: string): ParseResult => {
         );
 
         if (indexOfNextClose > index) {
+          const target = token.attrGet("href") as string;
           parsedLinks.push({
-            target: token.attrGet("href") as string,
+            target,
             content: tokens
               .slice(index + 1, indexOfNextClose)
               .map((t) => t.content)
               .join(""),
+            sourceLocation: sourceLocationOf(`(${target})`, content),
           });
         }
       }
 
-      if (token.type === "image")
+      if (token.type === "image") {
+        const src = token.attrGet("src") as string;
         parsedImages.push({
-          src: token.attrGet("src") as string,
+          src,
           alt: token.content,
+          sourceLocation: sourceLocationOf(`(${src})`, content),
         });
+      }
 
       if (token.children) scan(token.children);
     });
diff --git a/support/src/sourceLocation.ts b/support/src/sourceLocation.ts
new file mode 100644
index 00000000..9eecdbb9
--- /dev/null
+++ b/support/src/sourceLocation.ts
@@ -0,0 +1,22 @@
+export type SourceLocation = {
+  readonly line0: number;
+  readonly column0: number;
+};
+
+export const sourceLocationOf = (
+  needle: string,
+  haystack: string,
+): SourceLocation | null => {
+  const index = haystack.indexOf(needle);
+  if (index < 0) return null;
+
+  const lines = haystack.substring(0, index).split("\n");
+  const lastLine = lines.pop();
+  const line0 = lines.length;
+  const column0 = lastLine!.length;
+
+  return {
+    line0,
+    column0,
+  };
+};
diff --git a/validateLinks.ts b/support/src/validateLinks.ts
similarity index 67%
rename from validateLinks.ts
rename to support/src/validateLinks.ts
index 2c4d3a53..968b57a2 100644
--- a/validateLinks.ts
+++ b/support/src/validateLinks.ts
@@ -4,17 +4,26 @@ import { readFile } from "node:fs/promises";
 import { parse, type ParseResult } from "./parse.js";
 import path, { dirname, normalize } from "node:path/posix";
 import { isAbsolute } from "node:path";
+import type { SourceLocation } from "./sourceLocation.js";
 
 type ParsedFile = ParseResult & { readonly filename: string };
 
-const findAllFilesInGit = async (): Promise<string[]> => {
+const findAllFiles = async (): Promise<string[]> => {
   return await new Promise((resolve, reject) => {
-    exec("git ls-files -z", (error, stdout, stderr) => {
-      if (error) reject(error);
-      if (stderr)
-        reject(new Error(`git ls-files outputted on stderr: ${stderr}`));
-      else resolve(stdout.split("\0").filter(Boolean));
-    });
+    exec(
+      "find . -mindepth 1 -name node_modules -prune -o -name .git -prune -o -print0",
+      (error, stdout, stderr) => {
+        if (error) reject(error);
+        if (stderr) reject(new Error(`'find' outputted on stderr: ${stderr}`));
+        else
+          resolve(
+            stdout
+              .split("\0")
+              .filter(Boolean)
+              .map((s) => s.substring(2)), // Remove leading "./"
+          );
+      },
+    );
   });
 };
 
@@ -34,11 +43,23 @@ const scanForLinks = async (filenames: string[]): Promise<ParsedFile[]> => {
   );
 };
 
+const showError = (
+  filename: string,
+  sourceLocation: SourceLocation | null,
+  code: string,
+  message: string,
+) => {
+  const src = sourceLocation
+    ? `${sourceLocation.line0 + 1}:${sourceLocation.column0 + 1}`
+    : "0";
+  console.log(`${filename}:${src} ${code} ${message}`);
+};
+
 const externalLinkPattern = /^\w+:/;
 const isExternalLink = (t: string) => externalLinkPattern.test(t);
 
 const main = async () => {
-  const gitFiles = await findAllFilesInGit();
+  const gitFiles = await findAllFiles();
 
   // For now, we assume that there are no case clashes
   const lowercaseGitFiles = gitFiles.map((s) => s.toLocaleLowerCase());
@@ -56,8 +77,11 @@ const main = async () => {
         const exists = lowercaseGitFiles.includes(resolved.toLocaleLowerCase());
 
         if (!exists) {
-          console.log(
-            `error BROKEN-INTERNAL-IMAGE ${parsedFile.filename}:0 Broken internal image reference ${img.src}`,
+          showError(
+            parsedFile.filename,
+            img.sourceLocation,
+            "VL002/missing-image-target",
+            `Image source does not exist: ${img.src}`,
           );
           ++errors;
         }
@@ -90,8 +114,11 @@ const main = async () => {
         );
 
         if (!isFile && !isDirectory) {
-          console.log(
-            `error BROKEN-INTERNAL-LINK ${parsedFile.filename}:0 Link target does not exist: ${target}`,
+          showError(
+            parsedFile.filename,
+            link.sourceLocation,
+            "VL001/missing-link-target",
+            `Link target does not exist: ${target}`,
           );
           ++errors;
         }
diff --git a/support/src/watch.ts b/support/src/watch.ts
new file mode 100644
index 00000000..7f4ed5b5
--- /dev/null
+++ b/support/src/watch.ts
@@ -0,0 +1,81 @@
+import { spawn, type ChildProcess } from "node:child_process";
+import { watch } from "node:fs";
+
+const args = process.argv.slice(2);
+if (args.length === 0) {
+  console.error("Usage: node watch.js COMMAND [ARGS...]");
+  process.exit(1);
+}
+
+type State =
+  | {
+      readonly tag: "waiting";
+    }
+  | {
+      readonly tag: "delaying";
+    }
+  | {
+      readonly tag: "running-clean";
+      readonly child: ChildProcess;
+    }
+  | {
+      readonly tag: "running-dirty";
+      readonly child: ChildProcess;
+    };
+
+const cmdAndArgs = args;
+let state: State = { tag: "waiting" };
+
+const markAsDirty = () => {
+  if (state.tag === "waiting") {
+    setTimeout(startRun, 200);
+    state = { tag: "delaying" };
+  } else if (state.tag === "running-clean") {
+    state = {
+      ...state,
+      tag: "running-dirty",
+    };
+  } else if (state.tag === "running-dirty") {
+    //
+  }
+};
+
+const startRun = () => {
+  console.log("Spawning child process");
+  const child = spawn(cmdAndArgs[0], cmdAndArgs.slice(1), {
+    stdio: ["ignore", "inherit", "inherit"],
+  });
+
+  child.on("close", (code, signal) => {
+    if (code) {
+      console.log(`Child process failed: exited with code ${code}`);
+    } else if (signal) {
+      console.log(`Child process failed: killed by ${signal}`);
+    } else {
+      console.log(`Child process succeeded`);
+    }
+
+    if (state.tag === "running-clean") {
+      console.log("Waiting...");
+      state = { tag: "waiting" };
+    } else if (state.tag === "running-dirty") {
+      startRun();
+    }
+  });
+
+  state = {
+    tag: "running-clean",
+    child,
+  };
+};
+
+const listener = (event: string, filename: string | null) => {
+  console.log(`Watcher event: ${event} ${filename}`);
+  if (filename?.startsWith(".git/")) return;
+  if (filename?.startsWith("node_modules/")) return;
+  markAsDirty();
+};
+
+watch(".", { recursive: true, encoding: "binary" }, listener);
+console.log("Initiating first run");
+startRun();
diff --git a/tsconfig.json b/support/tsconfig.json
similarity index 91%
rename from tsconfig.json
rename to support/tsconfig.json
index beb9c155..8560e8c6 100644
--- a/tsconfig.json
+++ b/support/tsconfig.json
@@ -3,6 +3,7 @@
     "target": "ESNext",
     "module": "NodeNext",
     "moduleResolution": "nodenext",
+    "rootDir": "./src/",
     "outDir": "./dist/",
     "esModuleInterop": true,
     "forceConsistentCasingInFileNames": true,