This extension brings the File System Access API to Firefox that helps web apps such as https://vscode.dev read and write local files and folders. Main features: * Implemented showOpenFilePicker, showDirectoryPicker, showSaveFilePicker functions and related interfaces. * Set to enable specific File System Access features on matching web pages. * Provides File System Access API for other compatible WebExtensions. Notes: * The local file operations required by this extension cannot be performed in the browser, and a helper app needs to be installed to assist in the related work. * The optional Code Editor feature is provided by the Code Editor extension. Limitations: * By default, FileSystemHandle will lose its instance methods after cloning (e.g. using IndexedDB or postMessage), and requires additional configuration of the FS_CONFIG.CLONE_ENABLED. Web developers can use __FILE_SYSTEM_TOOLS__.parseHandle(handle) to restore the instance methods. * Limited Worker context support and requires additional configuration of the FS_CONFIG.WORKER_ENABLED. * Read file size is limited by the FS_CONFIG.FILE_SIZE_LIMIT. Web developers can read large file streams and slices with handle.getFile({ _allowNonNative: true }), and write large file in-place with handle.createWritable({ _inPlace: true, keepExistingData: true }). * DataTransferItem.prototype.getAsFileSystemHandle is not implemented. This extension is open source and you can file bug reports or feature requests on the GitHub issue. References: * https://wicg.github.io/file-system-access/