I use factions but there was a plugin I saw called Guilds I was thinking about using. A lot of people get annoyed with factions on my server as I use set factions, as in I have one non PvP faction and two warring PVP factions, each run by a mod, and players can just join them. I prefer this way to everybody being able to create factions and there ending up being hundreds which just get abandoned.
However I like the way they create PvP in groups. It also grows the community when there are set factions. My server is also an RPG server so the factions are named Norse, Greek etc. Each faction has a theme and it's something I enjoy having on my server.
