I search for methods to upload larger files with modern browsers.

I'd like take a file-upload in browser. analyses them. split it into small packets and upload them each by each up to my Server who join any package again to one file.

Maybe also generate a hash of the full file in browser, who can send at the end to server to compare and works fine.

I didn't like to use flash or other addons methods for it. Just with pure HTML5/Javascript on the client side.

How is it possible? ( I know its possible. Microsoft Skydrive already do it. But it's not possible to see how :-( )

Many Thanks for any help.