CodeShare.io - Realtime code sharing for developers
Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
Code2Flow - An easy solution to create product flows.
LaTeXDraw - LaTeXDraw is a graphical drawing editor for LaTeX.
CodePile - A simple, free & rich collaborative code sharing experience
Ipe - Ipe is a drawing editor for creating figures in PDF or (encapsulated) Postscript format.