When we are at it, we could probly add alot of software to the list. But the reason i think i want to use gimp is because it is probly the software that looks most like photoshop. Both when it comes to menus and tools. So it is probly alot easier to navigate menus and tools to find the same things in gimp, that are being shown on th videos. I dont know this a 100%, but i am guessing it.
