>According to what I found, only text files (like prgs) can be checked out by multiple users at the same time. But that makes me wonder what is the scctext.prg supposed to do in this case?

SCCTEXT.PRG is used to compare versions, since comparing the VCX (binary files) will only tell you if they are identical or different.

You could always get rid of you VCX and declare your classes through code, but I admit it's not an easy solution.