The /prog/ challenge

Let's do a game: I challenge you to write a program. Whoever wins can challenge other players to write another application of his choice. You can also make the game harder imposing certain conditions. Rule: no impossible requests.
I'll start with a simple one:
Write a simple XML Parser in less than 250 lines of code in C.

>>7
cpp -P prog.c | tr \\n \  > EXPERT-prog.c