You're probably thinking of the =(eGO)= 24/7 Dust2 server and yes, it is VERY popular. It is not a Deathmatch server though and instead runs like regular CS would with the twist of having upwards of 64 players in the server versus a traditional 5v5 or 10v10 team setup. It can be a little hectic, but it is still a LOT of fun, especially since they limit the use of AWPs and Auto snipers.