NGINX [Engine-X] is an HTTP(S) server, HTTP(S) reverse proxy and IMAP/POP3 proxy server written by Igor Sysoev. It has been running on many heavily loaded sites, including Facebook, Zappos, Groupon, LivingSocial, Hulu, TechCrunch, Dropbox, Tumblr and WordPress.
x0 (Xzero) is a low-latency, scalarable and modular HTTP Web Server and Framework written in C++.
Atop of its thin core HTTP layer, it supports plenty of plugins, and amongst them, the most prominent are the SSL plugin (based on GNU TLS) and the advanced load balancer plugin, featuring different
... [More] backend protocols (HTTP and FastCGI), dynamic creation/updating/deletion of backends, and much more... [Less]