Another reason why every critical-system programmer should learn and relearn the lessons of Therac-25.[http://courses.cs.vt.edu/~cs3604/lib/Therac_25/Therac_1.html]

agreed. I read about that as a case study for my CS "computing, society and professionalism" class.

for the therac one of their main problems was relying on software 100% and not having hardware failsafes as well.

I interned for a (rather large) medical software company. There was multiple rounds of red tape just to get a VB-based preference selector updated.

(In this specific case it's probably not a bad thing, just not my style.)