diff --git a/.github/workflows/gh-pages-deploy.yml b/.github/workflows/gh-pages-deploy.yml
index f689d4f..3424e6e 100644
--- a/.github/workflows/gh-pages-deploy.yml
+++ b/.github/workflows/gh-pages-deploy.yml
@@ -6,7 +6,7 @@ on:
   push:
     branches: main
   # Allows you to run this workflow manually from the Actions tab on GitHub.
-  # eslint-disable-next-line yml/no-empty-mapping-value
+  # eslint-disable-next-line yml/no-empty-mapping-value -- does not accept any value
   workflow_dispatch:
 
 # Allow this job to clone the repo and create a page deployment
diff --git a/.remarkrc.js b/.remarkrc.cjs
similarity index 100%
rename from .remarkrc.js
rename to .remarkrc.cjs
diff --git a/eslint.config.mjs b/eslint.config.mjs
index d0ec744..43196fd 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -1,141 +1,151 @@
-import html from 'eslint-plugin-html';
 import globals from 'globals';
-import path from 'node:path';
-import { fileURLToPath } from 'node:url';
-import { FlatCompat } from '@eslint/eslintrc';
-import mdxeslint from 'eslint-plugin-mdx';
-import jseslint from '@eslint/js';
-import tseslint from 'typescript-eslint';
-import eslintPluginAstro from 'eslint-plugin-astro';
-import eslintConfigPrettier from 'eslint-config-prettier';
+import pluginJs from '@eslint/js';
+import pluginTypeScript from 'typescript-eslint';
 import eslintPluginYml from 'eslint-plugin-yml';
+import eslintPluginAstro from 'eslint-plugin-astro';
 import eslintPluginJsonc from 'eslint-plugin-jsonc';
+import eslintPluginHtmlInlineScripts from 'eslint-plugin-html';
+import eslintConfigPrettier from 'eslint-config-prettier';
+import eslintPluginHtml from '@html-eslint/eslint-plugin';
+import eslintPluginHtmlParser from '@html-eslint/parser';
+import eslintPluginMdx from 'eslint-plugin-mdx';
+import { dirname } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { FlatCompat } from '@eslint/eslintrc';
+
+// TODO: Change to import.meta.dirname once Node 18 is no longer supported (Node >= >=20.11.0)
+const __dirname = dirname(fileURLToPath(import.meta.url));
 
-const __filename = fileURLToPath(import.meta.url);
-const __dirname = path.dirname(__filename);
 const compat = new FlatCompat({
   baseDirectory: __dirname
 });
 
+/** @type {import('eslint').Linter.Config[]} */
 export default [
-  {
-    files: [
-      '**/*.js',
-      '**/*.jsx',
-      '**/*.cjs',
-      '**/*.mjs',
-      '**/*.html',
-      '**/*.yml',
-      '**/*.yaml',
-      '**/*.md',
-      '**/*.mdx',
-      '**/*.json',
-      '**/*.jsonc',
-      '**/*.ts',
-      '**/*.tsx',
-      '**/*.astro'
-    ]
-  },
+  ...[
+    ...compat.extends('jquery'),
+    {
+      languageOptions: {
+        sourceType: 'script',
+        ecmaVersion: 5,
+        globals: { ...globals.browser, ...globals.jquery }
+      },
+      rules: {
+        'one-var': ['error', { var: 'consecutive' }],
+        strict: ['error', 'function'],
+        'no-nested-ternary': 0,
+        camelcase: 0,
+        'no-console': ['error', { allow: ['warn', 'error'] }]
+      }
+    }
+  ].map((cfg) => ({
+    ignores: [
+      'site/**',
+      '!site/src/components/demos/**/map.{js,html}',
+      '**/*.{mjs,cjs}'
+    ],
+    ...cfg
+  })),
   {
     ignores: [
-      'tests/redist/',
-      'examples/redist/',
-      '**/build/',
-      '**/dist/',
-      '**/node_modules/',
-      '!.github',
-      '!.vscode',
-      '**/package-lock.json',
-      '!**/.*.json',
-      '!**/.*.jsonc',
-      'docs/',
-      '**/*.d.ts',
-      '**/.astro/'
+      '**/redist/**',
+      '**/build/**',
+      '**/dist/**',
+      '**/.astro/**',
+      'docs/**'
     ]
   },
-  jseslint.configs.recommended,
-  ...compat.extends('jquery'),
-  eslintConfigPrettier,
-  ...eslintPluginYml.configs['flat/standard'],
-  ...eslintPluginYml.configs['flat/prettier'],
-  ...eslintPluginJsonc.configs['flat/recommended-with-jsonc'],
-  ...eslintPluginAstro.configs.recommended,
   {
-    plugins: {
-      html
-    },
-    linterOptions: {
-      reportUnusedDisableDirectives: true
-    },
+    files: ['site/src/components/demos/**/map.js'],
     languageOptions: {
-      globals: {
-        ...globals.browser,
-        ...globals.jquery
-      },
-      ecmaVersion: 5,
-      sourceType: 'script'
-    },
-    settings: {
-      'html/indent': '+2',
-      'html/report-bad-indent': 'error'
-    },
-    rules: {
-      'one-var': ['error', { var: 'consecutive' }],
-      strict: ['error', 'function'],
-      'no-nested-ternary': 0,
-      camelcase: 0,
-      'no-console': ['error', { allow: ['warn', 'error'] }]
+      parserOptions: {
+        ecmaFeatures: {
+          // these files are directly displayed in `Scripts` tab in website so avoid having to include use strict
+          impliedStrict: true
+        }
+      }
     }
   },
   {
-    ...mdxeslint.flat,
-    processor: mdxeslint.createRemarkProcessor({
+    files: ['.remarkrc.cjs'],
+    languageOptions: { globals: { ...globals.node } }
+  },
+  pluginJs.configs.recommended,
+  ...pluginTypeScript.config({
+    files: ['site/**/*.{js,mjs,cjs,ts}'],
+    ignores: ['site/src/components/demos/**/map.js'],
+    extends: [
+      pluginTypeScript.configs.strictTypeChecked,
+      pluginTypeScript.configs.stylisticTypeChecked
+    ],
+    languageOptions: {
+      parserOptions: {
+        project: true,
+        tsconfigRootDir: `${__dirname}/site`
+      }
+    }
+  }),
+  ...eslintPluginAstro.configs.recommended,
+  {
+    ...eslintPluginMdx.flat,
+    processor: eslintPluginMdx.createRemarkProcessor({
       lintCodeBlocks: true
     }),
     rules: {
-      ...mdxeslint.flat.rules,
+      ...eslintPluginMdx.flat.rules,
       'no-unused-vars': 'off'
     }
   },
-  mdxeslint.flatCodeBlocks,
   {
-    files: ['**/*.mjs'],
-    languageOptions: {
-      ecmaVersion: 'latest',
-      sourceType: 'module'
+    ...eslintPluginMdx.flatCodeBlocks,
+    rules: {
+      ...eslintPluginMdx.flatCodeBlocks.rules,
+      'no-var': 'off',
+      '@typescript-eslint/no-unused-vars': 'off',
+      '@typescript-eslint/no-require-imports': 'off'
     }
   },
   {
-    files: ['.remarkrc.js'],
+    // Configuration for `<script>` tag using TypeScript in `.astro` files and code blocks in markdown.
+    files: ['site/**/*.astro/*.ts', 'site/**/*.{md,mdx}/*.js'],
     languageOptions: {
-      globals: {
-        ...globals.node
+      parserOptions: {
+        project: false
       }
+    },
+    rules: {
+      ...pluginTypeScript.configs.disableTypeChecked.rules
     }
   },
+  ...eslintPluginYml.configs['flat/recommended'],
+  ...eslintPluginJsonc.configs['flat/recommended-with-jsonc'],
   {
-    files: ['site/**/*'],
+    ...eslintPluginHtml.configs['flat/recommended'],
+    files: ['**/*.html'],
+    plugins: {
+      eslintPluginHtmlInlineScripts,
+      '@html-eslint': eslintPluginHtml
+    },
     languageOptions: {
-      ecmaVersion: 'latest',
-      sourceType: 'module'
+      parser: eslintPluginHtmlParser
+    },
+    settings: {
+      'html/indent': '+2',
+      'html/report-bad-indent': 'error'
+    },
+    rules: {
+      ...eslintPluginHtml.configs['flat/recommended'].rules,
+      '@html-eslint/require-img-alt': 'off',
+      /* Disable rules that conflict with prettier */
+      '@html-eslint/require-closing-tags': 'off',
+      '@html-eslint/no-multiple-empty-lines': 'off',
+      '@html-eslint/no-extra-spacing-attrs': 'off',
+      '@html-eslint/element-newline': 'off',
+      '@html-eslint/indent': 'off',
+      '@html-eslint/quotes': 'off',
+      '@html-eslint/no-trailing-spaces': 'off',
+      '@html-eslint/attrs-newline': 'off'
     }
   },
-  ...tseslint.config({
-    files: ['site/**/*.ts'],
-    extends: [tseslint.configs.recommended],
-    languageOptions: {
-      parserOptions: {
-        project: true,
-        tsconfigRootDir: `${__dirname}/site`
-      }
-    }
-  }),
-  {
-    files: ['site/astro.config.mjs'],
-    languageOptions: {
-      globals: {
-        ...globals.node
-      }
-    }
-  }
+  eslintConfigPrettier
 ];
diff --git a/examples/altimages.html b/examples/altimages.html
index 84bfaf2..0b36f0c 100644
--- a/examples/altimages.html
+++ b/examples/altimages.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>AltImages Demo</title>
diff --git a/examples/autoresize.html b/examples/autoresize.html
index a70e430..ecc9fb3 100644
--- a/examples/autoresize.html
+++ b/examples/autoresize.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>Automatic Resize Demo</title>
@@ -183,7 +183,7 @@ <h2>Automatic Resize Demo</h2>
           style="width: 100%"
         />
       </div>
-      <div style="clear: both" />
+      <div style="clear: both"></div>
     </div>
     <div style="border: 5px solid orange; padding: 20px; margin: 40px">
       <img
diff --git a/examples/boundlist.html b/examples/boundlist.html
index dbb0eb1..b2c2b92 100644
--- a/examples/boundlist.html
+++ b/examples/boundlist.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>Bound List Test</title>
@@ -69,26 +69,6 @@
             );
         }
 
-        // eslint-disable-next-line no-unused-vars
-        function getBoundListForAreas(areas) {
-          var listItems = $.map(areas, function (area) {
-            var $a = $(area),
-              key = $a.data('name'),
-              description = $a.data('description');
-
-            return buildListItem(key, description);
-          });
-          return $veglist.empty().append(listItems).find('input');
-        }
-
-        // eslint-disable-next-line no-unused-vars
-        function getBoundListFromItems(items) {
-          var listItems = $.map(items, function (item) {
-            return buildListItem(item.key, item.value);
-          });
-          return $veglist.empty().append(listItems).find('input');
-        }
-
         var $image = $('#veg_image'),
           $veglist = $('#veg_list'),
           imageOptions = {
diff --git a/examples/frog.html b/examples/frog.html
index 44312ac..7196e35 100644
--- a/examples/frog.html
+++ b/examples/frog.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>Frog Menu Demo</title>
diff --git a/examples/includekeys.html b/examples/includekeys.html
index de15fe2..86bebc5 100644
--- a/examples/includekeys.html
+++ b/examples/includekeys.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>IncludeKeys Test</title>
diff --git a/examples/index.html b/examples/index.html
index 7522c17..7c3c16d 100644
--- a/examples/index.html
+++ b/examples/index.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>ImageMapster Examples</title>
diff --git a/examples/manualresize.html b/examples/manualresize.html
index c54187c..59c9569 100644
--- a/examples/manualresize.html
+++ b/examples/manualresize.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>Manual Resize Demo</title>
diff --git a/examples/multiple-maps.html b/examples/multiple-maps.html
index 4136b6c..f01d282 100644
--- a/examples/multiple-maps.html
+++ b/examples/multiple-maps.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>Multiple Maps Demo</title>
diff --git a/examples/navigate-full-frame.html b/examples/navigate-full-frame.html
index 3f1f679..1a47369 100644
--- a/examples/navigate-full-frame.html
+++ b/examples/navigate-full-frame.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>Navigation Demo - Full Frame</title>
diff --git a/examples/navigate-full.html b/examples/navigate-full.html
index e35105a..c3722b1 100644
--- a/examples/navigate-full.html
+++ b/examples/navigate-full.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>Navigation Demo - Full</title>
diff --git a/examples/navigate-simple.html b/examples/navigate-simple.html
index c0c9b80..fedf595 100644
--- a/examples/navigate-simple.html
+++ b/examples/navigate-simple.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>Navigation Demo - Simple</title>
diff --git a/examples/navigate-target.html b/examples/navigate-target.html
index baa0056..f27b8ef 100644
--- a/examples/navigate-target.html
+++ b/examples/navigate-target.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>Navigation Target Demo</title>
diff --git a/examples/nohref.html b/examples/nohref.html
index ee436df..6bdccf3 100644
--- a/examples/nohref.html
+++ b/examples/nohref.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>Nohref & Href Attribute Values Test</title>
diff --git a/examples/rebind.html b/examples/rebind.html
index aa54d0f..eb5233f 100644
--- a/examples/rebind.html
+++ b/examples/rebind.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>Rebind Test</title>
diff --git a/examples/scalebounds.html b/examples/scalebounds.html
index f39e19a..78696a8 100644
--- a/examples/scalebounds.html
+++ b/examples/scalebounds.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>Scaling Boundary Demo</title>
diff --git a/examples/shapes-ie.html b/examples/shapes-ie.html
index 044b3f4..4ded20a 100644
--- a/examples/shapes-ie.html
+++ b/examples/shapes-ie.html
@@ -1,3 +1,4 @@
+<!-- eslint-disable @html-eslint/require-lang, @html-eslint/require-doctype -- Ensure IE quirks mode compatibility -->
 <html>
   <head>
     <title>Shapes Demo - IE</title>
@@ -25,7 +26,7 @@
       $(document).ready(function () {
         'use strict';
 
-        // eslint-disable-next-line no-unused-vars
+        // eslint-disable-next-line no-unused-vars -- placeholder parameter
         function state_change(data) {
           //alert(data.state+":"+data.selected);
         }
diff --git a/examples/shapes-spec.html b/examples/shapes-spec.html
index 3f18b83..34cfd92 100644
--- a/examples/shapes-spec.html
+++ b/examples/shapes-spec.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>Shapes HTML Spec Test</title>
diff --git a/examples/shapes.html b/examples/shapes.html
index 7dbdcd0..a67afdd 100644
--- a/examples/shapes.html
+++ b/examples/shapes.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <title>Shapes Demo</title>
     <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
@@ -27,7 +27,7 @@
       $(document).ready(function () {
         'use strict';
 
-        // eslint-disable-next-line no-unused-vars
+        // eslint-disable-next-line no-unused-vars -- placeholder parameter
         function state_change(data) {
           //alert(data.state+":"+data.selected);
         }
diff --git a/examples/skeleton.html b/examples/skeleton.html
index 72d9e1a..cd18edd 100644
--- a/examples/skeleton.html
+++ b/examples/skeleton.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>Skeleton Joints Demo</title>
@@ -1134,7 +1134,7 @@ <h2>Skeleton Joints Demo</h2>
               key="L_Hip"
               >T</span
             >
-            <input type="checkbox" id="jl_R_Hip_swol" name="L_Hip" /><span
+            <input type="checkbox" id="jl_L_Hip_swol" name="L_Hip" /><span
               style="font-size: smaller"
               class="sel"
               key="L_Hip"
@@ -1146,7 +1146,7 @@ <h2>Skeleton Joints Demo</h2>
             style="font-size: small; float: left; padding-left: 3px"
           >
             <label style="font-weight: bolder">R:</label>
-            <input type="checkbox" id="jl_L_Hip_tend" name="R_Hip" /><span
+            <input type="checkbox" id="jl_R_Hip_tend" name="R_Hip" /><span
               style="font-size: smaller"
               class="sel"
               key="R_Hip"
diff --git a/examples/staticstate.html b/examples/staticstate.html
index fc6f792..62279dc 100644
--- a/examples/staticstate.html
+++ b/examples/staticstate.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>StaticState Test</title>
diff --git a/examples/tooltips.html b/examples/tooltips.html
index 1dda91e..3a70c1d 100644
--- a/examples/tooltips.html
+++ b/examples/tooltips.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>Tooltip Examples</title>
@@ -84,7 +84,7 @@
             $('#shapeimage').mapster('tooltip');
           }
         });
-        // eslint-disable-next-line no-unused-vars
+        // eslint-disable-next-line no-unused-vars  -- placeholder parameter
         function state_change(data) {
           //alert(data.state+":"+data.selected);
         }
diff --git a/examples/usa.html b/examples/usa.html
index 731e98e..d91aebd 100644
--- a/examples/usa.html
+++ b/examples/usa.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>USA Demo</title>
@@ -98,7 +98,7 @@ <h2>USA Demo</h2>
       <div style="clear: both; height: 8px"></div>
       <div>
         <div style="clear: both"></div>
-        <b>Using This Demonstration</b>
+        <h3>Using This Demonstration</h3>
         <ul>
           <li>
             Change rendering options for highlight or select and click "update"
@@ -145,7 +145,7 @@ <h2>USA Demo</h2>
         <table>
           <tr>
             <th colspan="3">
-              <h1>Image Size</h1>
+              <h3>Image Size</h3>
             </th>
           </tr>
           <tr>
@@ -158,10 +158,10 @@ <h1>Image Size</h1>
 
           <tr>
             <th>
-              <h1>Highlight Types</h1>
+              <h3>Highlight Types</h3>
             </th>
-            <th><h1>Selection Styles</h1></th>
-            <th><h1>Options</h1></th>
+            <th><h3>Selection Styles</h3></th>
+            <th><h3>Options</h3></th>
           </tr>
           <tr>
             <td width="33%" valign="top">
diff --git a/examples/vegetables.html b/examples/vegetables.html
index 33d0ccd..7b93e28 100644
--- a/examples/vegetables.html
+++ b/examples/vegetables.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
     <title>Vegetables Demo</title>
diff --git a/gruntfile.js b/gruntfile.cjs
similarity index 98%
rename from gruntfile.js
rename to gruntfile.cjs
index f446143..b42a699 100644
--- a/gruntfile.js
+++ b/gruntfile.cjs
@@ -1,9 +1,6 @@
-// eslint-disable-next-line no-undef
 var doccoNext = require('docco-next');
 
-// eslint-disable-next-line strict, no-undef
 module.exports = function (grunt) {
-  // eslint-disable-next-line no-undef
   require('jit-grunt')(grunt, {
     'bump-only': 'grunt-bump',
     'bump-commit': 'grunt-bump'
diff --git a/package-lock.json b/package-lock.json
index e7f0cd7..128d0fd 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -11,6 +11,8 @@
       "devDependencies": {
         "@eslint/eslintrc": "^3.2.0",
         "@eslint/js": "^9.17.0",
+        "@html-eslint/eslint-plugin": "^0.31.1",
+        "@html-eslint/parser": "^0.31.0",
         "docco-next": "^0.9.14",
         "eslint": "^9.17.0",
         "eslint-config-jquery": "^3.0.2",
@@ -212,6 +214,42 @@
         "node": "^18.18.0 || ^20.9.0 || >=21.1.0"
       }
     },
+    "node_modules/@html-eslint/eslint-plugin": {
+      "version": "0.31.1",
+      "resolved": "https://registry.npmjs.org/@html-eslint/eslint-plugin/-/eslint-plugin-0.31.1.tgz",
+      "integrity": "sha512-1DaqJmHx9Dnx9qAkJTTEhrV3uzxwO6ON+uCOK/zg7abxgrtnr1VzZQ+mnSI82oFyv9dfoee6DH+fJ3WF/ocLqA==",
+      "dev": true,
+      "dependencies": {
+        "@html-eslint/template-parser": "^0.31.0"
+      },
+      "engines": {
+        "node": "^12.22.0 || ^14.17.0 || >=16.0.0"
+      }
+    },
+    "node_modules/@html-eslint/parser": {
+      "version": "0.31.0",
+      "resolved": "https://registry.npmjs.org/@html-eslint/parser/-/parser-0.31.0.tgz",
+      "integrity": "sha512-yBDMnk1XYNrA4nCSG2KGUAb2PQyajmQFfZQlZG8PVr3JxR/y8i45JIFsaxxBq3B5GtMOAIq2NEF604vl6LmzXA==",
+      "dev": true,
+      "dependencies": {
+        "es-html-parser": "^1.0.0-alpha.4"
+      },
+      "engines": {
+        "node": ">=8.10.0"
+      }
+    },
+    "node_modules/@html-eslint/template-parser": {
+      "version": "0.31.0",
+      "resolved": "https://registry.npmjs.org/@html-eslint/template-parser/-/template-parser-0.31.0.tgz",
+      "integrity": "sha512-y4r401OpWsUYmo934uC8E5iLdVJrs5JRuJmkCp6rkNGILDwxj0fOhVmis0rxaCdVgO1i7QQm7SyTIgy1JO3G+Q==",
+      "dev": true,
+      "dependencies": {
+        "es-html-parser": "^1.0.0-alpha.4"
+      },
+      "engines": {
+        "node": "^12.22.0 || ^14.17.0 || >=16.0.0"
+      }
+    },
     "node_modules/@humanfs/core": {
       "version": "0.19.1",
       "resolved": "https://registry.npmjs.org/@humanfs/core/-/core-0.19.1.tgz",
@@ -2197,6 +2235,12 @@
         "node": ">= 0.4"
       }
     },
+    "node_modules/es-html-parser": {
+      "version": "1.0.0-alpha.4",
+      "resolved": "https://registry.npmjs.org/es-html-parser/-/es-html-parser-1.0.0-alpha.4.tgz",
+      "integrity": "sha512-5KUgd64goEPG1ZwP3rf/D+uAbdjyuNon0YY9u1yzR2NkFwa1UwxpsCQkzalAOlQaXAVtP32LGYRW4IAKAwo/sg==",
+      "dev": true
+    },
     "node_modules/es-object-atoms": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/es-object-atoms/-/es-object-atoms-1.0.0.tgz",
diff --git a/package.json b/package.json
index 6c51f0e..2e027dc 100644
--- a/package.json
+++ b/package.json
@@ -70,6 +70,8 @@
   "devDependencies": {
     "@eslint/eslintrc": "^3.2.0",
     "@eslint/js": "^9.17.0",
+    "@html-eslint/eslint-plugin": "^0.31.1",
+    "@html-eslint/parser": "^0.31.0",
     "docco-next": "^0.9.14",
     "eslint": "^9.17.0",
     "eslint-config-jquery": "^3.0.2",
diff --git a/site/astro.config.mjs b/site/astro.config.mjs
index 997e635..996227b 100644
--- a/site/astro.config.mjs
+++ b/site/astro.config.mjs
@@ -9,8 +9,8 @@ const sharedConfig = {
   // astro hasn't made import.meta.env available yet so we need
   // to use process to obtain variables
   // https://github.com/withastro/astro/issues/3897#issuecomment-1181381500
-  base: process.env.BASE_PATH || 'ImageMapster',
-  site: process.env.SITE_URL || 'https://jamietre.github.io',
+  base: ensureLeadingSlash(process.env.BASE_PATH ?? 'ImageMapster'),
+  site: process.env.SITE_URL ?? 'https://jamietre.github.io',
   // github pages redirects to trailingSlash urls so force dev
   // server to use them to help ensure we are using proper
   // paths and avoid unnecessary 301's by GH servers
@@ -19,8 +19,6 @@ const sharedConfig = {
 
 export default defineConfig({
   ...sharedConfig,
-  site: process.env.SITE_URL || 'https://jamietre.github.io',
-  base: ensureLeadingSlash(process.env.BASE_PATH || 'ImageMapster'),
   vite: {
     resolve: {
       /*
diff --git a/site/src/components/demos/usa/map.js b/site/src/components/demos/usa/map.js
index 972a005..ba4c96a 100644
--- a/site/src/components/demos/usa/map.js
+++ b/site/src/components/demos/usa/map.js
@@ -8,12 +8,14 @@ $(function () {
       render_highlight: {
         fillColor: '2aff00',
         stroke: true,
-        altImage: `https://raw.githubusercontent.com/jamietre/ImageMapster/master/examples/images/usa_map_720_alt_4.jpg`
+        altImage:
+          'https://raw.githubusercontent.com/jamietre/ImageMapster/master/examples/images/usa_map_720_alt_4.jpg'
       },
       render_select: {
         fillColor: 'ff000c',
         stroke: false,
-        altImage: `https://raw.githubusercontent.com/jamietre/ImageMapster/master/examples/images/usa_map_720_alt_5.jpg`
+        altImage:
+          'https://raw.githubusercontent.com/jamietre/ImageMapster/master/examples/images/usa_map_720_alt_5.jpg'
       },
       fadeInterval: 50,
       mapKey: 'data-state',
diff --git a/site/src/components/demos/vegetables/map.js b/site/src/components/demos/vegetables/map.js
index 0e1fcb3..946800c 100644
--- a/site/src/components/demos/vegetables/map.js
+++ b/site/src/components/demos/vegetables/map.js
@@ -1,6 +1,6 @@
 $(function () {
   // a cross reference of area names to text for each area's tooltip
-  const xref = {
+  var xref = {
       carrots: '<b>Carrots</b> are delicious and may turn your skin orange!',
       asparagus:
         "<b>Asparagus</b> is one of the first vegetables of the spring. Being a dark green, it's great for you, and has interesting side effects.",
diff --git a/site/src/components/disqus.astro b/site/src/components/disqus.astro
index 9d9d9d1..b39f276 100644
--- a/site/src/components/disqus.astro
+++ b/site/src/components/disqus.astro
@@ -30,8 +30,7 @@ const { pageId, pageUrl } = Astro.props;
   }
 </style>
 <script is:inline>
-  // NOTE - This must be a var as its wrapped by disqus which expects
-  // it on window.disqus_config and it modifies `this`
+  // eslint-disable-next-line no-var -- disqus expects it on window.disqus_config
   var disqus_config = function () {
     const container = document.getElementById('disqus_thread');
     this.page.url = container.dataset.disqusUrl;
diff --git a/src/core.js b/src/core.js
index 5c426ce..998f2cd 100644
--- a/src/core.js
+++ b/src/core.js
@@ -106,7 +106,7 @@
       when: {
         all: function (deferredArray) {
           // TODO: Promise breaks ES5 support
-          // eslint-disable-next-line no-undef
+          // eslint-disable-next-line no-undef -- requires polyfill per imagemapster docs
           return Promise.all(deferredArray);
         },
         defer: function () {
@@ -116,7 +116,7 @@
           // polyfill via native promise
           var Deferred = function () {
             // TODO: Promise breaks ES5 support
-            // eslint-disable-next-line no-undef
+            // eslint-disable-next-line no-undef  -- requires polyfill per imagemapster docs
             this.promise = new Promise(
               function (resolve, reject) {
                 this.resolve = resolve;
diff --git a/src/jqueryextensions.js b/src/jqueryextensions.js
index 88694c6..4034570 100644
--- a/src/jqueryextensions.js
+++ b/src/jqueryextensions.js
@@ -18,7 +18,7 @@
       });
       window.addEventListener('testPassive.mapster', function () {}, opts);
       window.removeEventListener('testPassive.mapster', function () {}, opts);
-      // eslint-disable-next-line no-unused-vars
+      // eslint-disable-next-line no-unused-vars -- intentionally ignoring
     } catch (e) {
       // intentionally ignored
     }
@@ -81,7 +81,7 @@
  *
  * Requires: jQuery >= 1.2.3
  */
-/* eslint-disable one-var */
+/* eslint-disable one-var -- code directly from jquery source */
 (function ($) {
   'use strict';
 
diff --git a/tests/global.tests.js b/tests/global.tests.js
index 6b0912d..ea3031f 100644
--- a/tests/global.tests.js
+++ b/tests/global.tests.js
@@ -7,7 +7,7 @@ Shared resources, setup & teardown. This must be included for all tests.
 /* global iqtest */
 /* exported image areas map_options u */
 
-/* eslint-disable no-unused-vars */
+/* eslint-disable no-unused-vars -- globals used by other test files */
 var image,
   areas,
   map_options,
diff --git a/tests/imagemapster-test-runner.html b/tests/imagemapster-test-runner.html
index 69873d2..56c5fce 100644
--- a/tests/imagemapster-test-runner.html
+++ b/tests/imagemapster-test-runner.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html>
+<html lang="en-US">
   <head>
     <title>ImageMapster Browser Test Runner</title>