I’m looking at libev, a replacement for libevent that provides the same features but with some important improvements, like a good documentation with nice examples, better support for multi-threaded programs (with different loops and fast intra-thread communication), file watchers, absolute timers, C++ support…

Here is a nice example of the libev performance: a very simple web server that can be embedded, only takes 188KB of memory, and it still beats all the other “fast” servers (ie, nginx).