This page is a work in progress. In the meantime, here are some links:
Rise of the Abyssal:
https://forum.zdoom.org/viewtopic.php?f=19&t=67815
or
https://www.doomworld.com/forum/topic/113165-rise-of-the-abyssal-single-level-tc/

MOTHER 25th Restoration Hack:
https://www.romhacking.net/hacks/5193/

The Whitewater Pact (unreleased):
https://www.reddit.com/r/thewhitewaterpact/

Santa Claus Conquers the Demons:
https://forum.zdoom.org/viewtopic.php?f=19&t=74095