From Eternity Wiki
- friendly monsters, including dogs, with behaviour inspired from real animals.
- other Dehacked flags and codepointers, increasing the modding possibility. Notable useful codepointers are Spawn, PlaySound and RandomJump, which can make new monsters and challenged highly customizable.
- the sky transfer linedef special, allowing arbitrary sky settings in maps, highly popular in modern megawads.
- more vanilla (and Boom) demo compatibility fixes.
- MBF on the DOOM Wiki.