IOCP has been in Windows since NT4, including all of the non-Server SKUs - from what I can tell, Win2k3+ is officially supported which means it will almost cert

IOCP has been in Windows since NT4, including all of the non-Server SKUs - from what I can tell, Win2k3+ is officially supported which means it will almost certainly work on >= XP. It's kind of funny to hear all the web folks talk about this "new cool IOCP API" :) If you do want to see a new cool API that Node.js should eventually take advantage of, check out User-Mode Scheduling in Win7+ at http://msdn.microsoft.com/en-us/library/dd627187(VS.85).aspx http://msdn.microsoft.com/en-us/library/dd627187(VS.85).aspx ; you can schedule your own async IO threads in userspace and save on kernel transitions.