is a Java program designed to simulate logic gates! AND, OR, XOR, NOT, NAND, NOR, EQV are all present.
I've been using it for approximately 15 minutes, and I'm loving it! Since it doesn't use an EXE wrapper, it can be launched completely from the command line on any platform! Just use java -jar LogicSim.jar while in the LogicSim directory or if you prefer, javaw -jar LogicSim.jar
Just make sure Java is in your PATH!
Waiting patiently for Windows 7, XHTML 2.0, CSS 3.0, PHP 6.0, the ratification of C++0x, and the day that I can code without logic troubles.