Ce programme libre et ludique de coloriage pour enfants
2D CAD for precise drawing
The Ipe extensible drawing editor
Paint brush program which you can draw objects, Object Painter
a race scenario drawing tool
Pencil2D is a cross-platform animation/drawing application.
Madeline 2.0 Pedigree Drawing Engine (PDE)
OBSOLETE; try http://drawpile.net/ instead!
Vector based drawing software designed for RPGs