GIMP is a well-known open-source image editor that is renown for its powerful features. GIMP Portable is a version of this program that can be taken on the go via installation on removable devices. Although for serious users GIMP likely will not knock Photoshop off the throne, but it's still a great option for anyone who's looking for a freeware alternative that offers a full complement of photo-editing tools.
GIMP Portable's interface will be familiar to anyone who's used Photoshop or similar image-editing programs; the image is placed in the center, with a toolbar down the left and additional palettes on the right. The toolbar icons are in color, which we found a little distracting, but we liked it that GIMP Portable let us fully customize which tools the toolbar displayed. We found the interface to be about as intuitive as any other image-editing software of this caliber; people who are experienced with other image editors will likely find it to be fairly standard and easy to navigate, while newbies will probably need to invest a significant amount of time into learning how GIMP works. The program offers a feature set that's typical of this type of application: advanced selection and perspective tools, global adjustments and filters, and the ability to work in layers for nondestructive editing. We had a few problems with GIMP Portable when it came to performance; there was significant lag on processor-heavy image transformations, and the program crashed twice when we tried to use the cage transform tool. We're not sure what caused this, but we recommend that you spend some time assessing the program for performance issues before getting too attached to it. GIMP Portable comes with ample documentation to help new users get started. Overall, GIMP Portable isn't perfect, but it's definitely worth checking out if you're in the market for a powerful, free image editor.
GIMP Portable installs and uninstalls without issues.