An example of a non-LPC MUD with a clearly identifiable mudlib is MUME, a DikuMUD that implements global support code in its language Mudlle.
As LPMud matured, the separation between driver and mudlib grew to the point that the developers of MudOS and DGD did not ship their drivers with fully functional mudlibs.
Nuclear War MUD is an LPMud running on the MudOS game driver and a custom mudlib once based on the LPMud 2.4.5 lib.