We use NGINX as our underlying platform, but have extensively extended it for our purposes. We actively contribute back to the NGINX open source community where there are developments we've made we think may be useful.

Sorry, but what/how exacly are you actively contributing? Other than yesterday's naive port of mod_pagespeed, I didn't find any of your contributions and you make it sound like something you're doing on the regular basis.

Don't get me wrong, I love the idea of your product from the very beginning, but don't say that you do things when you don't.

Yes, one of our engineers contributed a his work on a native port of mod_pagespeed two days ago. We have made a number of other contributions along the way as well, most of which aren't nearly as sexy as the one you pointed out. And we'll continue to do so.