Krita

Krita is an open source digital painting program that used to be part of the KOffice package - now it's split off into a separate thing.

It's got a lot to it. It's trying (and succeeding) to be a professional painting program. It offers a lot in the way of brushes, provides templates for various things (comics, movie stills etc) and has more modes and options than you can shake a stick at.

I'm pretty in love with it. It's powerful, but not as intimidating as something like Photoshop. It's also theme-able, which I like. I put it to the darker mode, because it looks the nicest. The colour-selector is very powerful - as well as the colour-wheel, triangle shade-picker, there are gradient/contrast/hue bars underneath. Makes it so much easier to adjust the colours.

Unfortunately, I can't wax lyrical about it much more, as I don't -know- much more. I'm kind of limited in my experience from only doing one drawing in it. I'll post about more features as I find them.