re: merrits of gimp
Gimp is pretty good, considering it's free. I wouldn't use it for pro-level graphic design, but, seemingly uniquely on the internet, I'm not actually a graphic designer for a living. My work does need me to chop things out of images occasionally, and it can do that competently.
Also note worthy in this line is UFRraw. Again, it's no lightroom, but I have a camera that's about 5 generations out of data (450D) and no one wants to pay me for my photos.
I'm well with those who wonder what purpose source forge fulfils in this day and age of github.