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doc/devdocs/common/monaco-editor.md

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+# Monaco Editor in PowerToys
+
+## Overview
+
+Monaco is the text editor that powers Visual Studio Code. In PowerToys, Monaco is integrated as a component to provide advanced text editing capabilities with features like syntax highlighting, line numbering, and intelligent code editing.
+
+## Where Monaco is Used in PowerToys
+
+Monaco is primarily used in:
+- Registry Preview module - For editing registry files
+- File Preview handlers - For syntax highlighting when previewing code files
+- Peek module - For preview a file
+
+## Technical Implementation
+
+Monaco is embedded into PowerToys' WinUI 3 applications using WebView2. This integration allows PowerToys to leverage Monaco's web-based capabilities within desktop applications.
+
+### Directory Structure
+
+The Monaco editor files are located in the relevant module directories. For example, in Registry Preview, Monaco files are bundled with the application resources.
+
+## Versioning and Updates
+
+### Current Version
+
+The current Monaco version can be found in the `loader.js` file, specifically in the variable named `versionMonaco`.
+
+### Update Process
+
+Updating Monaco requires several steps:
+
+1. Download the latest version of Monaco
+2. Replace/override the main folder with the new version
+3. Generate the new Monaco language JSON file
+4. Override the existing JSON file
+
+For detailed step-by-step instructions, see the [FilePreviewCommon documentation](FilePreviewCommon.md#update-monaco-editor).
+
+#### Estimated Time for Update
+
+The Monaco update process typically takes approximately 30 minutes.
+
+#### Reference PRs
+
+When updating Monaco, you can refer to previous Monaco update PRs as examples, as they mostly involve copy-pasting the Monaco source code with minor adjustments.
+
+## Customizing Monaco
+
+### Adding New Language Definitions
+
+Monaco can be customized to support new language definitions for syntax highlighting:
+
+1. Identify the language you want to add
+2. Create or modify the appropriate language definition files
+3. Update the Monaco configuration to recognize the new language
+
+For detailed instructions on adding language definitions, see the [FilePreviewCommon documentation](FilePreviewCommon.md#add-a-new-language-definition).
+
+### Adding File Extensions to Existing Languages
+
+To make Monaco handle additional file extensions using existing language definitions:
+
+1. Locate the language mapping configuration
+2. Add the new file extension to the appropriate language entry
+3. Update the file extension registry
+
+For detailed instructions on adding file extensions, see the [FilePreviewCommon documentation](FilePreviewCommon.md#add-a-new-file-extension-to-an-existing-language).
+
+Example: If Monaco processes TXT files and you want it to preview LOG files the same way, you can add LOG extensions to the TXT language definition.
+
+## Installer Handling
+
+Monaco source files are managed via a script (`Generate-Monaco-wxs.ps1`) that:
+1. Automatically generates the installer manifest to include all Monaco files
+2. Avoids manually listing all Monaco files in the installer configuration
+
+This approach simplifies maintenance and updates of the Monaco editor within PowerToys.