Mac OS X Server v10.6: Understanding process limits

Good info on process limits in Mac OS X
In versions of Mac OS X Server prior to version 10.6 (Snow Leopard) the maximum number of processes available on a server was limited to 2500. The 64-bit kernel included in Mac OS X Server v10.6 automatically scales the maximum number of processes, vnodes (open file handles), and threads based on the amount of memory installed in the server.