Matchmaking platforms
Services that start a server for each match, so their name is on hundreds of short-lived servers. Their players are real, but a server per match isn't a community, so they aren't ranked against communities.
RankCommunity
Playing now7-day averageServers
Communities are found from the website their servers' names share, or made by owners from servers they've claimed. Ranked by the average real players on all their servers over 7 days, updated hourly. Run one? Make or claim its page.