`twisted-iocpsupport` is an extension module for the Twisted `iocp` reactor to use the Windows I/O Completion Ports (IOCP) networking API. You should not need to install it directly or interact with its API; it is a dependency of Twisted on Windows platforms.
https://github.com/twisted/twisted/issues?q=is%3Aopen+is%3Aissue+label%3Aiocpreactor
