Hello, I suggest the developer of PCC writing a user manual, at least a introduction for the command line options. Thank you.
Another thing to do is documentation about pcc, maybe a book about compilers with emphasis of pcc internals (and porting).
One more good thing is to port it in every imaginable platform. This is a very ambitious project of course, but some platforms (ARM, MIPS, PowerPC,etc.) and operating systems (Haiku and FreeBSD) can be ported.