Fork-per-connection (sequential) is simple and pretty fast, but it does have its limits (it works fine for a simple webapp, but writing a high-performance IRC s

Fork-per-connection (sequential) is simple and pretty fast, but it does have its limits (it works fine for a simple webapp, but writing a high-performance IRC server that way will be rather painful.) Once you need more than fork-per-connection can easily provide, you're not doing sequential code, you're doing events and/or threads. "Threads suck" is a common theme lately, but both can be pretty complex. (Event-based code obscures control flow, as you note; threaded code is subject to very subtle and hard-to-reproduce bugs.)