At my last job we used Python to write the UI for controlling train brakes (electronically controlled pneumatic railway brakes). Worked really well for us since

At my last job we used Python to write the UI for controlling train brakes (electronically controlled pneumatic railway brakes). Worked really well for us since we did a buttload of testing (with robotframework http://code.google.com/p/robotframework/ http://code.google.com/p/robotframework/ and a bunch of other things).