I remember using the (old) DigLog digital logic simulator to construct digital circuits. The feature that made this program so fun was “glow mode“. I want to let my Digital Electronics classes experience digital simulation.

Norman Hedrick at the University of Hamburg wrote a program similar to DigLog. The program is java-based, so it can run on Windows / Mac OS X / Linux. Even better, the program doesn’t need to be installed, it can be run from it’s webpage.
I recommend you check out: