I got My-Paint installed and working on my computer, with Ubuntu 12.04. I am having a load of fun with it because I can load brushes and effects from hundreds of other users. The software seems simple and bug free, and the quality of brushes and backgrounds seem very professional. I fired it up, and it responded well to my graphic tablet, so off I went painting my heart out!
Like anything that is free and open source, the interface is not that impressive, but once you start going through all of the functions, the program starts to really shine. It is a simple interface, with just the bare necessities for painting and drawing with. The colour wheel is simple, and the brush pallet is straight forward. Perhaps that is what is needed, simplicity; only having what is needed on your Desktop, rather than having hundreds of widgets plastered all over the screen.
I pushed My-Paint to the limit, creating an image that was well over 200MB and it handled it well, even with unlimited “un-do” on, and it kept on going until I was finished–way better than some of the commercial products I used in the past.
I really had to play around with the brushes to get some of the effects I wanted. Oil Paints, for example, the effect of 3D paint on the brushes was not even close to what some of the Pro Software have, but nonetheless the brushes had their good points, you just needed to tweak them a lot to get what you want. Free is free, and I am not complaining.