Users can embed this free photo editor directly into their browser, download the editor into mobile apps for both iOS and Android, or download the standalone software.
GIMP (GNU Image Manipulation Project; Open Source)
An open source software, GIMP a good alternative to Photoshop, and is freely available for download on many operating systems. Users new to the software may find the free e-book Grokking the GIMP helpful; there are also many YouTube and other web tutorials available for specific GIMP commands.
Like Aviary, Pixlr is a free web-based photo editor that lets users manipulate and edit photos in their browsers. Users in search of photos to edit might like the Pixlr Grabber feature, which lets users select images from the web and edit immediately. Check out their blog for additional tips and tricks.