A side note left out in the history mentioned here is that Igor first[1] developed two third-party modules for Apache, mod_deflate and mod_accel[2]. I think esp

A side note left out in the history mentioned here is that Igor first[1] developed two third-party modules for Apache, mod_deflate and mod_accel[2]. I think especially the latter was a big step towards NGINX already. It was a much more capable replacement for the mod_proxy module that was bundled with Apache, and that would slurp up the response from the server as fast as it could, storing it in a local file cache while starting delivery to the client immediately (and optionally re-use the cache for future requests); it freed up the back-end server quickly, which was very helpful to reduce the number of concurrent processes in a system that used fork (as the Perl based systems I was working on did). It made performance better than FastCGI (as at least the Apache FastCGI implementation would not do the step of slurping up the response and copying it to a temporary file, and thus tie down the back-end process until the response was fully delivered to the client). My interpretation of the history is that Igor first solved the scalability problems for a direct need (IIRC he was working for a large Russian website at the time[3]), while doing that probably realized that the Apache code base could be replaced whole-sale to do more than just HTTP proxying, and introduced the async approach to make it scalable itself, too. [1] IIRC I saw the public NGINX announcement a few months after starting to use mod_accel. [2] Amazingly the page is still up: http://sysoev.ru/en/apache_modules.html http://sysoev.ru/en/apache_modules.html (and it is still linking to the "Babelfish English translation" that I made by auto-translating and manually cleaning up the docs and that I hosted on a DynDNS domain that I've long since lost). [3] Rambler, from reading the other comments here.