On the HHVM blog today they've posted an announcement about a new feature of this already powerful environment to help broaden the user base - FastCGI support.
Today, we are happy to announce FastCGI support for HHVM. FastCGI is a popular protocol for communication between an application server (e.g. running your PHP code) and a webserver. With support for FastCGI, you will be able to run HHVM behind any popular web server (Apache, Nginx, Lighttpd, etc). The webserver is in charge of handling all the intricate details of the HTTP protocol. HHVM is in charge of what it does best, running PHP code blazingly fast.
The post goes on to talk about how it all works including how it enables an instance of HHVM to run between requests (and serving multiple requests in parallel). It uses asynchronous I/O and a separate set of worker threads to execute the code. The rest of the post shares the results of a few benchmarks and gives you a step-by-step guide to getting it up and running.