Oh, so you don't want me to carry on with my reverse-engineering or whatever of the format? Fine by me - I just won't release any source code or players then.

Just so you know what I've found out so far: I've managed to work out the rough structure of the file, and also most of how instrument data is stored for a standard .MOD file. On the to-do list is to work out the pattern structures, and of course decode the file for other formats.