This channel uploads videos of doom speedrun records for various levels and categories found on Doom Speed Demo Archive: https://dsdarchive.com/.
Overview of about 250 playlists and more info can be found in this pastebin: https://pastebin.com/VWLkBmHF
Descriptions of the demos, like source port used or any comments, can be found by downloading the demo and reading the included txt file.
A 24/7 Twitch channel can be found here: https://www.twitch.tv/doomspeeddemos, where the demos are chosen at random from DSDArchive.
Source port used in recent videos is called DSDA-Doom.