I have been using Photoshop for as long as I can remember. Since I am expecting my new laptop, I am on a search for opensource programs. Adobe Photoshop CS3 Extended costs $999 and there is no way that I would ever buy it. Thats when I found GIMP…
It features layers, channels, paths and other common painting tools and can do almost anything Photoshop can. The interface is slightly different than Photoshop, but it is very easy to get used to. However, be aware, it takes a bit of playing around to understand all there is that you can do.
You can see a few features of GIMP here.
So, if you are still using a pirated version of Photoshop, GIMP is definately worth a look. If you have a genuine copy of Photoshop I recommend you stick with it.
My hope is that GIMP will be able to rival photoshop one day.