Asymptote is a powerful descriptive vector graphics language for technical drawing, inspired by MetaPost but with an improved C++-like syntax. Asymptote provides for figures the same high-quality typesetting that LaTeX does for scientific text.
LWCAD is a cross-platform 2D/3D CAD system working on Linux and Windows. It is released under GPL. LWCAD provides comprehensive 2D drafting features and powerful 3D modeling capabilities.