Vector Magic - Easily convert JPG, PNG, BMP, GIF bitmap images to SVG, EPS, PDF, AI, DXF vector images with real full-color tracing, online or using the desktop app!
GIMP - GIMP is a multiplatform photo manipulation tool.
Karbon - Karbon is the scalable vector drawing application in KDE.
Krita - Krita is a professional FREE and open source painting program. It is made by artists that want to seaffordable art tools for everyone. Concept art. texture and matte painters, illustrations and comics.
AutoTrace - It is tracing program, so converts bitmap to vector graphics.
MyPaint - MyPaint is a fast, distraction-free, and easy painting tool for digital artists.