Программирование, веб, python, django и многое-многое другое
The key principle seems to be: do not rely on an action, but on the structure of the system. Make the default, a passive state, a safe state so that when the system fails, it gets to the safe state by default. (via Brett Slatkin)
http://rjlipton.wordpress.com/2010/02/08/trains-elevators-and-computer-science/