Gimp 1oth Anniversary
The Gimp is an Open Source project that doesn’t sucktm. It has many good qualities, and some that aren’t good (I really hate the UI–as do many people, more about that some other time.)
As a replacement for Photoshop it is lacking in some areas (the, afore-mentioned, UI, gif animation, image map slicing, and CMYK color management), and excels in others (scriptability, extensibility, portability–you can use it on Unix, Mac, and Windows, and price–free as in freedom, and beer.)
Rock on Wilber!