I tend to agree, I've only used it as a learning experience. I tend to go with threads-shared-memory. IIRC SysV shared mem had a nasty habit of not destroying itself automatically, leaving these security gaps if you are not careful. I have seen some patches that address this problem, but threads are my first choice of tool now. I would be willing to bet that SysV shared-mem is faster than threads-shared-mem, if proper tests were done, but if you really need that kind of millisec speed increase, you should write it in c or assembly :-) . Of course, if you have to fork, instead of threading, SysV Shared mem still provides a good way of IPC between forked processes.