Cross-Platform Version Control
An interesting post by Eric Sink at SourceGear on some quirks you run into building a cross-platform version control system. I like this one:
Under Linux, checkin a file with a name that ends in a dot. Check it out under Windows. The trailing dot is probably gone. Now check the file back in and go back to your Unix system. If your version control system handled this badly, you've probably got two copies of the file, one with the trailing dot, and one without. Same goes for a trailing space.