The ivykis library is a thin, portable wrapper around os-provided mechanisms such as epoll(4), kqueue(2) and poll(2). it was mainly designed for building high-performance network applications, but can be used in any event-driver application that uses pollable file descriptors as its event sources.

programs written to the ivykis api are generally single-threaded (or use only a small number of threads), and never block on i/o. all input and output is done in a nonblocking fashion, with i/o readiness notification delivered via callback functions.