[jan_k_]

The most active multiplayer Doom port is Zandronum, using the Doomseeker server browser to join games. Mac support may be a bit flaky, but I think it currently works (join the Discord for help).

https://zandronum.com/ - get the software, join the discord

https://doomlist.net/ - see active servers

[AgentME]

I've always much preferred Zandronum over Zdaemon because it's open source and it has much more advanced mod capabilities (with much more Zdoom/Gzdoom mod support than Zdaemon), supporting mods adding game modes like the PVE Invasion mode.