JavaScript only file uploader with progress bar

Does anybody know how they do multi file upload using only Javascript only and still show smooth progress bar fo开发者_开发问答r each file? I've seen gmail, hotmail and amazon s3 do it.

I've used plupload and swfupload. Both provide SWF multiple file upload methods with progress bars but plupload also provides HTML5, Silverlight, BrowserPlus alternatives and a plain form fallback. Both are quite configurable but I use plupload for the extra levels of browser/plugin support.

NOTE: plupload site appears to be down, I'd assume this is temporary as the project is still active.

you can use jquery with HTML5 to do this , See this example http://code.google.com/p/jquery-html5-upload/source/browse/trunk/example.html

An excelent plugin (if not the best) is Uploadify

http://www.uploadify.com/

Hope this helps. Cheers