From Six Revisions:

Web-based image editors have several advantages to its desktop counterparts. The most obvious benefit is that they allow you to work on any computer (that has a browser). In most cases, you can save your work online, avoid having to install desktop software, and interface with other web based services such as Flickr or Picasa. This article shares 6 of the finest, free online image editors that are capable alternatives to desktop applications like Adobe Photoshop and GIMP.

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