Bukkit

MobSpawnControl = Focuses on limiting the numbers of mobs spawning from a single spawner. This works really well for worlds where you aren't allowing players to place spawners (ie. creative, modded worlds). I personally like mob grinders and I think players do also which is why I wanted to keep them in the game. However.. massive grinders can bring your server to its knees. Thus I decided the best way to solve this problem was to track monsters originating from a single spawner. This brings a very consistent experience to the player while limiting the impact to the server. The negative side is that you will still see variable performance impact based on the number of monsters active in a given chunk. However overall performance will definitely be better than a vanilla server since I've placed a limit on the number of monsters that can pop from a spawner.

ChunkSpawnerLimiter = Cyprias takes a slightly different approach to solving this problem. He decided the best way to manage this was to limit the number of monsters in a given chunk. He tackles the "wandering monster" problem by searching surrounding chunks before allowing the spawner to execute a new spawn. This definitely adds some overall consistency to server performance since each chunk should never exceed a given number of monster entities. However this does add some inconsistency to player experience since their particular spawner may stop spawning entirely if someone else has already consumed all of the monster limit for that chunk. PRO = more consistent server performance than MSC. CON = less consistent user experience than MSC.

MaxTPS = Katuma takes the same approach as CSL. PROs and CON appear to be the same as CSL although I haven't stepped all the way through the code.

NoLagg = bergerkiller limits all creatures in a chunk so farm animals are affected as well. This is probably the MOST consistent for server performance since it limits the total number of entities (animals and monsters) in a chunk. PRO = Arguably the most consistent server performance. CON = arguably the least consistent for user experience since it affects both monsters and farm animals.