Wikipedia
Libuv
libuv is a software library that provides asynchronous event notification. libuv supports epoll(4), kqueue(2), Windows IOCP, and Solaris event ports. It is primarily designed for use in Node.js but it is also used by other software projects. It was originally an abstraction around libev or Microsoft IOCP, as libev doesn't support Windows. In node-v0.9.0's version of libuv, the dependency on libev was removed.