Reply 60 of 60, by auron
as it says on those github pages, one is a zdoom fork while the other is a gzdoom fork. of course brutal doom needs the GL features to work properly. i actually got the regular release of v21 to run acceptably with this version, the only problem i've ran into is that upon a midi track ending there's a message complaining about lack of memory despite having another 250mb of free RAM, and i had to restart the audio system to get the music back.
one useful tweak for anyone running into this issue: i've been wondering why this fork ignores the refresh rate set in windows and just runs at 60hz (which is kept even after exiting the game, at least under 98se), but as it turns out, there's an ini variable "vid_refreshrate" for this and its set to 0 by default.