Krita

Krita is a full-featured digital painting application designed for artists. Whether you create illustrations, comics, animations, concept art or storyboards – Krita will be a powerful tool for you. Krita offers many common and innovative features to make painting more fun and more productive. There are great brush engines for sketching and painting, stabilizers for freehand inking, assistants for constructing a complex scene, a distraction-free canvas-only mode for painting without bother, clone layers, filter and transform masks for non-destructive editing. You can exchange files with other applications in many different formats. Krita comes with translations in many languages.