A Windows port of Caffeine for OS X. I used to use Insomnia, and in fact stole most of the code from that app, but I wanted a friendlier interface.
Uses free icons from VisualPharm.
This fork contains an automatic mode, that prevents sleep as long as a process with a given name is running. The names can be configured, one line per process, named as in the task manager (case sensitive). Tested with iTunes, to keep it playing.
I also wanted to keep the computer awake without the screen on (based on another fork), but this does not seem to work. Any info on this is welcome.