Some really nice Q3 maps seem to be coming out recently, is there still a decent community for this? I thought Quake Live was dead? Has something else taken over? 

There are still a lot of levels downloaded every day. It seems like (based on the people that contact me) that there are a lot people running small LANs. These seem 3 to 5 people home and office LANs. People running custom versions of OpenArena and others running stock Q3A using ioquake3. The Quake3World Forum is still fairly active as well. As to Quake Live - never tried it. Does it even run on Linux? 

I went to the local arcade near me and they had a bunch of PCs which were running Open Arena, no idea how popular that is as no-one was playing it at the time (lots of people playing overwatch and CS though).

I installed Quake Live recently but it seems no-one is playing FFA (my fave mode), everyone was playing Clan Arena instead. There was probably >100 active players if I am to believe the numbers I was seeing (and assuming that those servers weren't using bots). I was really bummed out about this tbh, looks like Quake Champions has not only cannibalised itself but also killed off the Quake Live community too.

As for ioquake3 I haven't tried it, but I should probably check it out to see how standard Q3 fares. Maybe all the Q3 players jumped back to the original game?