OpenResty (aka. ngx_openresty) is a full-fledged web application server by bundling the standard Nginx core, lots of 3rd-party Nginx modules, as well as most of their external dependencies.
http://openresty.org/#Components
Yet another damn fork?
OpenResty is not an Nginx fork. It is just a software bundle. Most of the patches applied to the Nginx core in OpenResty
have already been submitted to the official Nginx team and most of the
patches submitted have also been accepted. We are trying hard not to fork Nginx and always to use the latest best Nginx core from the official Nginx team.