While it's not exactly a "source port", Vanilla Doom still has a large fanbase/numerous enthusiasts and all the resources a vanilla Doomer might want are (were) scattered about all over the place.   This is my attempt to make a comprehensive Vanilla Doom thread so that any vanilla enthusiast, be them a player, mapper, or tinkerer in general might find what they need.     Vanilla Doom General:   ZIP containing all variants of the Vanilla Doom 1.9 EXE - LINK