GIMP is a free open source graphics editor that has been around since 1995. The name stands for GNU Image Manipulaton Program and it is available for Windows, Mac and Linux operating systems.
Right now GIMP is probably the best truely free graphics editing software that you’ll find. It supports multiple layers, vector layers and plugins. GIMP is usable for photo editing and has most of the tools for basic and intermediate level graphics design, even vector graphics editing is doable.
The interface is a bit more complex and confusing than some of the other free graphics editors, but overall it has more features and many of these features tend to work better than the alternatives once you figure out how to use them.
The software is actively maintained and developed by volunteers associated with the openn source GNU and GNOME projects with the help of donations from both individuals and corporations.
If you are new to GIMP, you may want to check out my basic photo editing tutorial. It should provide you with the basics of how to use GIMP and get you started with photo editing and a little bit of graphics design.
Plugin and scripting support.
Point-to-point selection tool.
Tools and filters for photo retouching, including brightness, contrast and color adjustment filters, and clone brush tool.
Multiple layer and vector layer support.
Available for Windows, Mac and Linux operating systems.