BrowserFS

"BrowserFS is an in-browser file system that emulates the Node JS file system API and supports storing and retrieving files from various backends. BrowserFS also integrates nicely into the Emscripten file system.

BrowserFS is highly extensible, and ships with many filesystem backends:

• XmlHttpRequest: Downloads files on-demand from a webserver via XMLHttpRequest
• LocalStorage: Stores files in the browser's localStorage.
• HTML5FS: Stores files into the HTML5 FileSystem API
• IndexedDB: Stores files into the browser's IndexedDB object database.
• Dropbox: Stores files into the user's Dropbox account.
  • Note: You provide this filesystem with an authenticated DropboxJS client
• InMemory: Stores files in-memory. Thus, it is a temporary file store that clears when the user navigates away.
• ZipFS: Read-only zip file-backed FS. Lazily decompresses files as you access them.
  • Supports DEFLATE out-of-the-box.
  • Have super old zip files? The browserfs-zipfs-extras package adds support for EXPLODE, UNREDUCE, and UNSHRINK.
• IsoFS: Mount an .iso file into the file system.
  • Supports Microsoft Joliet and Rock Ridge extensions to the ISO9660 standard.
• WorkerFS: Lets you mount the BrowserFS file system configured in the main thread in a WebWorker, or the other way around!
• MountableFileSystem: Lets you mount multiple file systems into a single directory hierarchy, as in *nix-based OSes.
• OverlayFS: Mount a read-only file system as read-write by overlaying a writable file system on top of it. Like Docker's overlayfs, it will only write changed files to the writable file system.
• AsyncMirrorFS: Use an asynchronous backend synchronously. Invaluable for Emscripten; let your Emscripten applications write to larger file stores with no additional effort!
  • Note: Loads the entire contents of the file system into a synchronous backend during construction. Performs synchronous operations in-memory, and enqueues them to be mirrored onto the asynchronous backend.
• FolderAdapter: Wraps a file system, and scopes all interactions to a subfolder of that file system.
• Emscripten: Lets you mount Emscripten file systems inside BrowserFS.

More backends can be defined by separate libraries, so long as they extend the BaseFileSystem. Multiple backends can be active at once at different locations in the directory hierarchy.

For more information, see the API documentation for BrowserFS."

https://github.com/jvilk/browserfs