PGF and TikZ - PGF/TikZ is a tandem of languages for producing vector graphics from a geometric/algebraic...
Playscii - Full-featured ASCII art and graphic editor and game creation tool
LaTeXDraw - LaTeXDraw is a graphical drawing editor for LaTeX.
PabloDraw - PabloDraw is an Ansi/Ascii text and RIPscrip vector graphic art editor/viewer with multi-user capabilities.
Diagrams Haskell package - Diagrams is a powerful, flexible, declarative domain-specific language for creating vector...
REXPaint - REXPaint is a powerful and user-friendly ASCII art editor.