"blue screen" in OS X ?

[XUN]

A friend of mine just had what it seems to be some kind of "blue screen" in OS X (Tiger 10.4.1). I took a picture. Is it possible to crash OS X ?? Has anyone observed anything similar ?

 

[wrldwzrd89]

I've seen that one before, on my own iMac G4 (it hasn't happened to me for 466 days and counting). Mac OS X does crash like that at times. The cause may be fairly obvious (unplugging a balky USB device stops the crashes) or not at all obvious (testing RAM, booting from another disk, using the Mac normally all result in crashes - in this case, the PMU settings were messed up; a PMU reset fixed the problem).