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.

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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.

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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

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An excelent plugin (if not the best) is Uploadify

http://www.uploadify.com/

Hope this helps. Cheers