diff --git a/arduino-ide-extension/src/browser/arduino-ide-frontend-module.ts b/arduino-ide-extension/src/browser/arduino-ide-frontend-module.ts
index f481dfc21..c85a94311 100644
--- a/arduino-ide-extension/src/browser/arduino-ide-frontend-module.ts
+++ b/arduino-ide-extension/src/browser/arduino-ide-frontend-module.ts
@@ -371,6 +371,7 @@ import { DebugSessionWidget } from '@theia/debug/lib/browser/view/debug-session-
 import { DebugConfigurationWidget } from './theia/debug/debug-configuration-widget';
 import { DebugConfigurationWidget as TheiaDebugConfigurationWidget } from '@theia/debug/lib/browser/view/debug-configuration-widget';
 import { DebugToolBar } from '@theia/debug/lib/browser/view/debug-toolbar-widget';
+import { InoHighlight } from './contributions/ino-highlight';
 
 // Hack to fix copy/cut/paste issue after electron version update in Theia.
 // https://github.com/eclipse-theia/theia/issues/12487
@@ -767,6 +768,7 @@ export default new ContainerModule((bind, unbind, isBound, rebind) => {
   Contribution.configure(bind, UpdateArduinoState);
   Contribution.configure(bind, BoardsDataMenuUpdater);
   Contribution.configure(bind, AutoSelectProgrammer);
+  Contribution.configure(bind, InoHighlight);
 
   bindContributionProvider(bind, StartupTaskProvider);
   bind(StartupTaskProvider).toService(BoardsServiceProvider); // to reuse the boards config in another window
diff --git a/arduino-ide-extension/src/browser/contributions/format.ts b/arduino-ide-extension/src/browser/contributions/format.ts
index c92741f1f..8c2813931 100644
--- a/arduino-ide-extension/src/browser/contributions/format.ts
+++ b/arduino-ide-extension/src/browser/contributions/format.ts
@@ -1,4 +1,3 @@
-import { MaybePromise } from '@theia/core';
 import { inject, injectable } from '@theia/core/shared/inversify';
 import * as monaco from '@theia/monaco-editor-core';
 import { Formatter } from '../../common/protocol/formatter';
@@ -15,13 +14,14 @@ export class Format
   @inject(Formatter)
   private readonly formatter: Formatter;
 
-  override onStart(): MaybePromise<void> {
+  override onStart(): void {
     monaco.languages.registerDocumentRangeFormattingEditProvider(
       InoSelector,
       this
     );
     monaco.languages.registerDocumentFormattingEditProvider(InoSelector, this);
   }
+
   async provideDocumentRangeFormattingEdits(
     model: monaco.editor.ITextModel,
     range: monaco.Range,
diff --git a/arduino-ide-extension/src/browser/contributions/ino-highlight.ts b/arduino-ide-extension/src/browser/contributions/ino-highlight.ts
new file mode 100644
index 000000000..89e57fe23
--- /dev/null
+++ b/arduino-ide-extension/src/browser/contributions/ino-highlight.ts
@@ -0,0 +1,558 @@
+import { inject, injectable } from '@theia/core/shared/inversify';
+import * as monaco from '@theia/monaco-editor-core';
+import { DEFAULT_WORD_REGEXP } from '@theia/monaco-editor-core/esm/vs/editor/common/core/wordHelper';
+import { StandardTokenType } from '@theia/monaco-editor-core/esm/vs/editor/common/encodedTokenAttributes';
+import { TokenizationTextModelPart } from '@theia/monaco-editor-core/esm/vs/editor/common/model/tokenizationTextModelPart';
+import { ITokenizationTextModelPart } from '@theia/monaco-editor-core/esm/vs/editor/common/tokenizationTextModelPart';
+import { SemanticTokensBuilder } from '@theia/plugin-ext/lib/plugin/types-impl';
+import { HostedPluginSupport } from '../hosted/hosted-plugin-support';
+import { InoSelector } from '../selectors';
+import { SketchContribution } from './contribution';
+
+interface TokenizationOwner {
+  readonly tokenization: ITokenizationTextModelPart;
+}
+
+function hasTokenization(arg: unknown): arg is TokenizationOwner {
+  return (
+    typeof arg === 'object' &&
+    arg !== null &&
+    (<TokenizationOwner>arg).tokenization !== undefined &&
+    (<TokenizationOwner>arg).tokenization instanceof TokenizationTextModelPart
+  );
+}
+
+@injectable()
+export class InoHighlight
+  extends SketchContribution
+  implements monaco.languages.DocumentSemanticTokensProvider
+{
+  @inject(HostedPluginSupport)
+  private readonly hostedPluginSupport: HostedPluginSupport;
+
+  private readonly _legend: monaco.languages.SemanticTokensLegend = {
+    tokenModifiers: [],
+    tokenTypes: vsCodeTokenTypeLiterals.slice(),
+  };
+
+  override onStart(): void {
+    monaco.languages.registerDocumentSemanticTokensProvider(InoSelector, this);
+  }
+
+  getLegend(): monaco.languages.SemanticTokensLegend {
+    return this._legend;
+  }
+
+  async provideDocumentSemanticTokens(
+    model: monaco.editor.ITextModel,
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars, unused-imports/no-unused-vars
+    lastResultId: string | null,
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars, unused-imports/no-unused-vars
+    token: monaco.CancellationToken
+  ): Promise<monaco.languages.SemanticTokens> {
+    await this.hostedPluginSupport.didStart;
+    const start = performance.now();
+    const builder = new SemanticTokensBuilder();
+    if (!hasTokenization(model)) {
+      return builder.build();
+    }
+    const parsedTokens = getHighlightedTokens(model);
+    for (const parsedToken of parsedTokens) {
+      builder.push(
+        parsedToken.line,
+        parsedToken.startCharacter,
+        parsedToken.length,
+        vsCodeTokenIndex[parsedToken.tokenType]
+      );
+    }
+    const tokens = builder.build();
+    console.log(
+      'provideDocumentSemanticTokens',
+      performance.now() - start + 'ms',
+      'lastResultId',
+      lastResultId
+    );
+    return tokens;
+  }
+
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
+  releaseDocumentSemanticTokens(lastResultId: string | undefined): void {
+    console.log('releaseDocumentSemanticTokens', 'lastResultId', lastResultId);
+    // NOOP
+  }
+}
+
+interface IParsedToken {
+  line: number;
+  startCharacter: number;
+  length: number;
+  tokenType: VSCodeTokenType;
+  tokenModifiers: string[];
+}
+
+const MAX_TOKENIZATION_LINE_LEN = 500; // If line is too long tokenization is skipped
+function getHighlightedTokens(
+  model: (monaco.editor.ITextModel & TokenizationOwner) | null
+): IParsedToken[] {
+  const result: IParsedToken[] = [];
+  if (!model) {
+    return result;
+  }
+
+  // For every word in every line, map its ranges for fast lookup
+  for (
+    let lineNumber = 1, len = model.getLineCount();
+    lineNumber <= len;
+    ++lineNumber
+  ) {
+    const lineLength = model.getLineLength(lineNumber);
+    // If line is too long then skip the line
+    if (lineLength > MAX_TOKENIZATION_LINE_LEN) {
+      continue;
+    }
+
+    const lineContent = model.getLineContent(lineNumber);
+    model.tokenization.resetTokenization();
+    model.tokenization.forceTokenization(lineNumber);
+    const lineTokens = model.tokenization.getLineTokens(lineNumber);
+    for (
+      let tokenIndex = 0, tokenCount = lineTokens.getCount();
+      tokenIndex < tokenCount;
+      tokenIndex++
+    ) {
+      const tokenType = lineTokens.getStandardTokenType(tokenIndex);
+
+      // Token is a word and not a comment
+      if (tokenType === StandardTokenType.Other) {
+        // reset the stateful regex
+        DEFAULT_WORD_REGEXP.lastIndex = 0; // We assume tokens will usually map 1:1 to words if they match
+
+        const tokenStartOffset = lineTokens.getStartOffset(tokenIndex);
+        const tokenEndOffset = lineTokens.getEndOffset(tokenIndex);
+        const tokenStr = lineContent.substring(
+          tokenStartOffset,
+          tokenEndOffset
+        );
+        const wordMatch = DEFAULT_WORD_REGEXP.exec(tokenStr);
+
+        if (wordMatch) {
+          const word = wordMatch[0];
+          const tokenType = getTokenType(word);
+          if (tokenType) {
+            result.push({
+              line: lineNumber - 1, // map monaco 1 index to protocol 0 index
+              startCharacter: tokenStartOffset + wordMatch.index,
+              length: word.length,
+              tokenModifiers: [],
+              tokenType,
+            });
+          }
+        }
+      }
+    }
+  }
+
+  return result;
+}
+
+const arduinoTokenTypeLiterals = [
+  'type',
+  'built_in',
+  '_hints',
+  'literal',
+] as const;
+type ArduinoTokenType = (typeof arduinoTokenTypeLiterals)[number];
+
+// https://code.visualstudio.com/api/language-extensions/semantic-highlight-guide#standard-token-types-and-modifiers
+const vsCodeTokenTypeLiterals = ['type', 'event', 'label', 'macro'] as const;
+type VSCodeTokenType = (typeof vsCodeTokenTypeLiterals)[number];
+const vsCodeTokenIndex = vsCodeTokenTypeLiterals.reduce((acc, curr, index) => {
+  acc[curr] = index;
+  return acc;
+}, {} as Record<VSCodeTokenType, number>);
+
+const arduinoToVSCodeMappings: Record<ArduinoTokenType, VSCodeTokenType> = {
+  _hints: 'event',
+  type: 'type',
+  built_in: 'type',
+  literal: 'macro',
+};
+
+let _tokens: Map<string, ArduinoTokenType> | undefined;
+function getTokenType(word: string): VSCodeTokenType | undefined {
+  if (!_tokens) {
+    const tokens = new Map();
+    for (const [type, words] of Object.entries(arduinoKeywords)) {
+      words.forEach((w) => tokens.set(w, type));
+    }
+    _tokens = tokens;
+  }
+  const token = _tokens.get(word);
+  if (!token) {
+    return undefined;
+  }
+  return arduinoToVSCodeMappings[token];
+}
+
+// Based on https://github.com/highlightjs/highlight.js/blob/6317acd780bfe448f75393ea42d53c0149013274/src/languages/arduino.js#L13-L378
+const arduinoKeywords = {
+  type: ['boolean', 'byte', 'word', 'String'],
+  built_in: [
+    'KeyboardController',
+    'MouseController',
+    'SoftwareSerial',
+    'EthernetServer',
+    'EthernetClient',
+    'LiquidCrystal',
+    'RobotControl',
+    'GSMVoiceCall',
+    'EthernetUDP',
+    'EsploraTFT',
+    'HttpClient',
+    'RobotMotor',
+    'WiFiClient',
+    'GSMScanner',
+    'FileSystem',
+    'Scheduler',
+    'GSMServer',
+    'YunClient',
+    'YunServer',
+    'IPAddress',
+    'GSMClient',
+    'GSMModem',
+    'Keyboard',
+    'Ethernet',
+    'Console',
+    'GSMBand',
+    'Esplora',
+    'Stepper',
+    'Process',
+    'WiFiUDP',
+    'GSM_SMS',
+    'Mailbox',
+    'USBHost',
+    'Firmata',
+    'PImage',
+    'Client',
+    'Server',
+    'GSMPIN',
+    'FileIO',
+    'Bridge',
+    'Serial',
+    'EEPROM',
+    'Stream',
+    'Mouse',
+    'Audio',
+    'Servo',
+    'File',
+    'Task',
+    'GPRS',
+    'WiFi',
+    'Wire',
+    'TFT',
+    'GSM',
+    'SPI',
+    'SD',
+  ],
+  _hints: [
+    'setup',
+    'loop',
+    'runShellCommandAsynchronously',
+    'analogWriteResolution',
+    'retrieveCallingNumber',
+    'printFirmwareVersion',
+    'analogReadResolution',
+    'sendDigitalPortPair',
+    'noListenOnLocalhost',
+    'readJoystickButton',
+    'setFirmwareVersion',
+    'readJoystickSwitch',
+    'scrollDisplayRight',
+    'getVoiceCallStatus',
+    'scrollDisplayLeft',
+    'writeMicroseconds',
+    'delayMicroseconds',
+    'beginTransmission',
+    'getSignalStrength',
+    'runAsynchronously',
+    'getAsynchronously',
+    'listenOnLocalhost',
+    'getCurrentCarrier',
+    'readAccelerometer',
+    'messageAvailable',
+    'sendDigitalPorts',
+    'lineFollowConfig',
+    'countryNameWrite',
+    'runShellCommand',
+    'readStringUntil',
+    'rewindDirectory',
+    'readTemperature',
+    'setClockDivider',
+    'readLightSensor',
+    'endTransmission',
+    'analogReference',
+    'detachInterrupt',
+    'countryNameRead',
+    'attachInterrupt',
+    'encryptionType',
+    'readBytesUntil',
+    'robotNameWrite',
+    'readMicrophone',
+    'robotNameRead',
+    'cityNameWrite',
+    'userNameWrite',
+    'readJoystickY',
+    'readJoystickX',
+    'mouseReleased',
+    'openNextFile',
+    'scanNetworks',
+    'noInterrupts',
+    'digitalWrite',
+    'beginSpeaker',
+    'mousePressed',
+    'isActionDone',
+    'mouseDragged',
+    'displayLogos',
+    'noAutoscroll',
+    'addParameter',
+    'remoteNumber',
+    'getModifiers',
+    'keyboardRead',
+    'userNameRead',
+    'waitContinue',
+    'processInput',
+    'parseCommand',
+    'printVersion',
+    'readNetworks',
+    'writeMessage',
+    'blinkVersion',
+    'cityNameRead',
+    'readMessage',
+    'setDataMode',
+    'parsePacket',
+    'isListening',
+    'setBitOrder',
+    'beginPacket',
+    'isDirectory',
+    'motorsWrite',
+    'drawCompass',
+    'digitalRead',
+    'clearScreen',
+    'serialEvent',
+    'rightToLeft',
+    'setTextSize',
+    'leftToRight',
+    'requestFrom',
+    'keyReleased',
+    'compassRead',
+    'analogWrite',
+    'interrupts',
+    'WiFiServer',
+    'disconnect',
+    'playMelody',
+    'parseFloat',
+    'autoscroll',
+    'getPINUsed',
+    'setPINUsed',
+    'setTimeout',
+    'sendAnalog',
+    'readSlider',
+    'analogRead',
+    'beginWrite',
+    'createChar',
+    'motorsStop',
+    'keyPressed',
+    'tempoWrite',
+    'readButton',
+    'subnetMask',
+    'debugPrint',
+    'macAddress',
+    'writeGreen',
+    'randomSeed',
+    'attachGPRS',
+    'readString',
+    'sendString',
+    'remotePort',
+    'releaseAll',
+    'mouseMoved',
+    'background',
+    'getXChange',
+    'getYChange',
+    'answerCall',
+    'getResult',
+    'voiceCall',
+    'endPacket',
+    'constrain',
+    'getSocket',
+    'writeJSON',
+    'getButton',
+    'available',
+    'connected',
+    'findUntil',
+    'readBytes',
+    'exitValue',
+    'readGreen',
+    'writeBlue',
+    'startLoop',
+    'IPAddress',
+    'isPressed',
+    'sendSysex',
+    'pauseMode',
+    'gatewayIP',
+    'setCursor',
+    'getOemKey',
+    'tuneWrite',
+    'noDisplay',
+    'loadImage',
+    'switchPIN',
+    'onRequest',
+    'onReceive',
+    'changePIN',
+    'playFile',
+    'noBuffer',
+    'parseInt',
+    'overflow',
+    'checkPIN',
+    'knobRead',
+    'beginTFT',
+    'bitClear',
+    'updateIR',
+    'bitWrite',
+    'position',
+    'writeRGB',
+    'highByte',
+    'writeRed',
+    'setSpeed',
+    'readBlue',
+    'noStroke',
+    'remoteIP',
+    'transfer',
+    'shutdown',
+    'hangCall',
+    'beginSMS',
+    'endWrite',
+    'attached',
+    'maintain',
+    'noCursor',
+    'checkReg',
+    'checkPUK',
+    'shiftOut',
+    'isValid',
+    'shiftIn',
+    'pulseIn',
+    'connect',
+    'println',
+    'localIP',
+    'pinMode',
+    'getIMEI',
+    'display',
+    'noBlink',
+    'process',
+    'getBand',
+    'running',
+    'beginSD',
+    'drawBMP',
+    'lowByte',
+    'setBand',
+    'release',
+    'bitRead',
+    'prepare',
+    'pointTo',
+    'readRed',
+    'setMode',
+    'noFill',
+    'remove',
+    'listen',
+    'stroke',
+    'detach',
+    'attach',
+    'noTone',
+    'exists',
+    'buffer',
+    'height',
+    'bitSet',
+    'circle',
+    'config',
+    'cursor',
+    'random',
+    'IRread',
+    'setDNS',
+    'endSMS',
+    'getKey',
+    'micros',
+    'millis',
+    'begin',
+    'print',
+    'write',
+    'ready',
+    'flush',
+    'width',
+    'isPIN',
+    'blink',
+    'clear',
+    'press',
+    'mkdir',
+    'rmdir',
+    'close',
+    'point',
+    'yield',
+    'image',
+    'BSSID',
+    'click',
+    'delay',
+    'read',
+    'text',
+    'move',
+    'peek',
+    'beep',
+    'rect',
+    'line',
+    'open',
+    'seek',
+    'fill',
+    'size',
+    'turn',
+    'stop',
+    'home',
+    'find',
+    'step',
+    'tone',
+    'sqrt',
+    'RSSI',
+    'SSID',
+    'end',
+    'bit',
+    'tan',
+    'cos',
+    'sin',
+    'pow',
+    'map',
+    'abs',
+    'max',
+    'min',
+    'get',
+    'run',
+    'put',
+  ],
+  literal: [
+    'DIGITAL_MESSAGE',
+    'FIRMATA_STRING',
+    'ANALOG_MESSAGE',
+    'REPORT_DIGITAL',
+    'REPORT_ANALOG',
+    'INPUT_PULLUP',
+    'SET_PIN_MODE',
+    'INTERNAL2V56',
+    'SYSTEM_RESET',
+    'LED_BUILTIN',
+    'INTERNAL1V1',
+    'SYSEX_START',
+    'INTERNAL',
+    'EXTERNAL',
+    'DEFAULT',
+    'OUTPUT',
+    'INPUT',
+    'HIGH',
+    'LOW',
+  ],
+} as const;
diff --git a/arduino-ide-extension/src/browser/data/dark.color-theme.json b/arduino-ide-extension/src/browser/data/dark.color-theme.json
index 9e9d15718..7539c76a1 100644
--- a/arduino-ide-extension/src/browser/data/dark.color-theme.json
+++ b/arduino-ide-extension/src/browser/data/dark.color-theme.json
@@ -89,7 +89,8 @@
       "scope": [
         "storage",
         "support",
-        "string.quoted.single.c"
+        "string.quoted.single.c",
+        "macro"
       ],
       "settings": {
         "foreground": "#0ca1a6"
@@ -101,7 +102,8 @@
         "meta.function.c",
         "entity.name.function",
         "meta.function-call.c",
-        "variable.other"
+        "variable.other",
+        "label"
       ],
       "settings": {
         "foreground": "#F39C12"
@@ -146,7 +148,8 @@
       "name": "meta keywords",
       "scope": [
         "keyword.control",
-        "meta.preprocessor.c"
+        "meta.preprocessor.c",
+        "event"
       ],
       "settings": {
         "foreground": "#C586C0"
diff --git a/arduino-ide-extension/src/browser/data/default.color-theme.json b/arduino-ide-extension/src/browser/data/default.color-theme.json
index e81e4baa0..89f90dcb1 100644
--- a/arduino-ide-extension/src/browser/data/default.color-theme.json
+++ b/arduino-ide-extension/src/browser/data/default.color-theme.json
@@ -89,7 +89,8 @@
       "scope": [
         "storage",
         "support",
-        "string.quoted.single.c"
+        "string.quoted.single.c",
+        "macro"
       ],
       "settings": {
         "foreground": "#00979D"
@@ -101,7 +102,8 @@
         "meta.function.c",
         "entity.name.function",
         "meta.function-call.c",
-        "variable.other"
+        "variable.other",
+        "label"
       ],
       "settings": {
         "foreground": "#D35400"
@@ -146,7 +148,8 @@
       "name": "meta keywords",
       "scope": [
         "keyword.control",
-        "meta.preprocessor.c"
+        "meta.preprocessor.c",
+        "event"
       ],
       "settings": {
         "foreground": "#728E00"