PGF is a TeX macro package for generating graphics. It is platform- and format-independent and works together with the most important TeX backend drivers, including pdftex and dvips. It comes with a user-friedly syntax layer called TikZ.
Agna is a freeware application designed for social network analysis, sociometry and sequential analysis. Platform-independent, friendly and easy-to-learn, integrated visual network editor, html output, free.
Now you can personalize your Twitter background like never before. The tool below will help you create free Twitter backgrounds that have the same look and feel as those done by professional graphic designers. It's easy to use, and best of all, it's Free! Give it a try!