Resumable.js, JavaScript magic for simultaneous, stable and resumable uploads : It’s a JavaScript library providing multiple simultaneous, stable and resumable uploads via the HTML5 File API. The library is designed to introduce fault-tolerance into the upload of large files through HTTP. This is done by splitting each files into small chunks; whenever the upload of a chunk fails, uploading is retried until the procedure completes. This allows uploads to automatically resume uploading after a network connection is lost either locally or to the server. Additionally, it allows for users to pause, resume and even recover uploads without losing state. via Tumblr http://scalper.tumblr.com/post/66156535763