Noah Gibbs' DGD, LPC & MUDLib Page(s)
Part of that is a collection of examples of how to do things with DGD's LPC.
Richard Braakman's DGD 1.1 Dumpfile Format documentation.
Erwin Harte wrote a quick'n'dirty example System-lib setup to demonstrate how easy it is to extend the kernel-lib that comes with DGD. The linked file is in mbox format and contains an attachment with a gzipped tar file.
Mikael Elemel Lind wrote an LPC function to make a deep copy of any LPC data-structure. You can find it in his repository.