Just wanted to make a tribute for this warm, devoted and most talented modding community of one of the best and epic DOS oldies.
One of the best modders there are IMHO Ceilick (art), Tulik (art and mapping) and Lemm (coding).
Lemm's greatest achivements are IMHO the multiplayer NetKeen.
The best Keen mods INHO are the TUIT ("The Universe is a Toast") trilogy, which is a rare example of commercial-quality product that is at least as good and professional as the original games - that take Keen to new places.... Desert, Snow, Asteroids......
Art and animation quality is amazing, so are the tiles and coding patches.
Keen source is not released so guys work with exe patches (!!!).
There is a work on "Keen for SDL" - aka "Commander Genius". When made it'll boost Keen modding even further.