Adobe Photoshop is good, but is not the only one out there to turn your memorable photos into works of art. The world of Open Source provides some really thought-provoking alternatives that do give Photoshop a run for the money (pun intended). The following tools are just what the doctor ordered if you are looking for free Photoshop alternatives.
Paint.NET is free image and photo editing software for PCs that run Windows. It features an intuitive and innovative user interface with support for layers, unlimited undo, special effects, and a wide variety of useful and powerful tools. An active and growing online community provides friendly help, tutorials, and plugins.
Use your graphics card to edit your pictures in a snap, without destroying them. ChocoFlop allows you to edit your photos or design stuff using Apple’s CoreImage technology. It takes advantage of the power of your graphics card (GPU). Because of this it can show real-time previews of filters and keep modifications live for as long as you want.
CinePaint is an open source computer program for painting and retouching bitmap frames of films. It is a fork of version 1.0.4 of the GNU Image Manipulation Program (GIMP).
Pixia is a freeware raster graphics editor program for Windows, created by Isao Maruoka. It was originally designed for the anime/manga community but has also been used in other branches of art. Besides the primary Japanese interface, it is also available in English, French, Italian, Spanish, Hungarian, Chinese Simplified, Chinese Traditional, Polish, Korean and German. The program supports multiple layers, transparency effects, standard file formats and a number of RGB file formats including .PSD.
Pixen is an open-source raster graphics editor for Mac OS X created by the Open Sword Group and presently maintained on GitHub. It is designed to create and edit pixel art and animations.
PhotoFiltre is a freeware created by Antonio Da Cruz. In addition to the conventional treatment of the image (cropping, contrast, gamma, etc), it has a hundred filters to improve and transform digital photos. It also allows you to add functionality to a system with PhotoFiltre plugins. Many programming languages are supported, allowing all developers with sufficient knowledge to create and share plugins.
Serif PhotoPlus is an image editing program for Microsoft Windows. The latest version is Serif PhotoPlus X6.
Xara Xtreme for Linux is a powerful, general purpose graphics program for Unix platforms including Linux, FreeBSD and (in development) OS-X. Formely known as Xara LX, it is based on Xara Xtreme for Windows, which is the fastest graphics program available, period.