“Many web applications use image uploaders: image hosting websites, blog publishing applications, social networks, among many others. Such uploaders have limitations: you can’t upload more than one file at a time and you can’t edit the image before sending it. A plugin is the usual workaround for uploading more than one image, and image modifications are usually done on the server side, which can make the editing process more cumbersome.

Firefox 3.6 allows millions of people to take advantage of modern standards, including HTML5.

The image uploader described here shows how a web page should really be considered as an application since it interacts with your Desktop and works offline.”

All the information here.