NGINX is free web server software (or HTTP) as well as a reverse proxy. Documentation is available in several languages. It is since April 2019, the most used web server in the world
NGINX is an asynchronous system as opposed to synchronous servers where each request is processed by a dedicated process. Instead of leveraging a parallel architecture and time division multiplexing of tasks by the operating system, NGINX uses state changes to manage multiple connections at the same time; the processing of each request is split into numerous mini-tasks and thus makes it possible to achieve efficient multiplexing between the connections. In order to take advantage of multiprocessor computers, several processes can be started. This choice of architecture results in very high performance, but also in a particularly low load and memory consumption compared to classic HTTP servers, such as Apache.