Links

http://www.cadsoft.de/
Whether you are a team of one, or part of a large engineering department, EAGLE provides quality PCB design software with the features that get the job done. For over 20 years, EAGLE has been satisfying design engineers around the world, by offering the same core functionality as expensive commercial software, at the fraction of the cost.

http://jd.benow.ca
Good Java classes decompiler.

http://code.google.com/p/java-simple-serial-connector/
Crossplatform (Win32/64, Linux32/64, MacOS, Solaris) Java-library for serial interface.

http://www.inkscape.org/
A free vector graphics editor

http://vim-adventures.com/
Lerning VIM vhile playing a game.