Just stumbled across this video through YouTube recommendations, "What I found by watching a twenty-year-old Doom II deathmatch"
It's quite an interesting retrospective on some aspects of the "scene" that existed in 1999
Here's the link to the video:
https://www.youtube.com/watch?v=w1QYD8Dz2FE
I personally have many fond memories of playing DOOM & DOOMII on the family computer back in the 90s then I clocked some serious time playing it in high school around 2005-2007 using the excellent program Doom Connector you can play it online co-op to this day (or deathmatch but that was never my thing since I was playing a lot of Quake 2 & Counter-Strike 1.5 at the time).
The website for Doom Connector is https://doomconnector.com and you can play it for free using freedoom which is a royalty free graphics replacement pack if you don't have a legal copy of the game you can use. Available here https://freedoom.github.io
There are hundreds of WAD files which are basically level packs or graphics replacements. They also ship many mods with DEH files which is a hack format that allows you to load in edited weapons so many mods will introduce lots of cool guns. The great thing about Doom Connector is it will automatically search the internet for these WAD/DEH files when you join a server so you can play heaps of varieties of game setups.
From his pinned comment on the video:
Had some great comments on the Doomworld and reddit threads:
https://www.doomworld.com/forum/topic/94894-what-i-found-by-watching-a-twenty-year-old-doom-ii-deathmatch/
https://www.reddit.com/r/Doom/comments/6l6d9w/what_i_found_by_watching_a_doom_ii_deathmatch/
definitely a very memorable game and before this it was the game wolfenstein 3d on our Pentium 386.