I had a go at a Rack/WSGI style PHP web server a while ago: http://getkelpie.com/ http://getkelpie.com/ .. it's using the mongrel http parser wrapped in a PHP

I had a go at a Rack/WSGI style PHP web server a while ago: http://getkelpie.com/ http://getkelpie.com/ .. it's using the mongrel http parser wrapped in a PHP extension, so it's pretty fast and reliable: https://github.com/dhotson/httpparser-php https://github.com/dhotson/httpparser-php I tried it at work and got pretty significant performance increase since it only has to initialize the framework at server startup instead of every request. We went from a baseline of 70ms to about 2ms per request.