wxArt2D gives wxWindows applications sophisticated vector drawing functionality.
It is based on a framework supporting multiple views within a hierarchical document. Supports drawing & (Graph) editing. In-output in SVG, GDSII, XML, easy to extend.
The Doodle project aims to provide a language to easily describe
Origami diagrams and produces a ready-to-print document. Doodle will
free creators from diagramming constraints and increase their capability
to share their creations.