# Developer Preview (Monaco) Developer preview is based on [Microsoft's Monaco Editor](https://microsoft.github.io/monaco-editor/) which is maintained by the Visual Studio Code team. ## Update monaco editor 1. Download Monaco editor with npm: `npm i monaco-editor`. 2. Delete everything except the `min` folder (the minimised code). 3. Copy the `min` folder inside the [`monacoSRC`](/src/modules/previewpane/MonacoPreviewHandler/monacoSRC) folder. 4. Generate the JSON file (see section below) ## monaco_languages.json [`monaco_languages.json`](/src/modules/previewpane/MonacoPreviewHandler/monaco_languages.json) contains all extensions and Id's for the supported languages of Monaco. The [`FileHandler`](/src/modules/previewpane/MonacoPreviewHandler/FileHandler.cs) class and the installer are using this file. ### Generate monaco_languages.json file After you updated monaco editor or adding a new language you should update the [`monaco_languages.json`](/src/modules/previewpane/MonacoPreviewHandler/monaco_languages.json) file. You have to run the file on a local webserver! 1. Build monaco in debug mode. 2. Open [generateLanguagesJson.html](/src/modules/previewpane/MonacoPreviewHandler/generateLanguagesJson.html) in a browser. 3. Replace the old JSON file.