They gave me a notebook, the task was to write a simple program (20 lines, no math or tricks, but more than a FizzBuzz) in a script language I've never seen before. They provided a correct documentation on the language (I've been should use the Internet, but I've only found the very same doc). They gave me 1 hour, but I've finished in 10 mins.
Then a semi-formal part came, asking about C/C++ techniques, concepts, but we've also discussed several topics, about clean code etc.