The Apache HTTP Server Project is an effort to develop and maintain an open-source HTTP server for various modern desktop and server operating systems, such as UNIX and Windows NT. The goal of this project is to provide a secure, efficient and extensible server which provides HTTP services in sync with the current HTTP standards. The 2.x branch of Apache Web Server includes several improvements like threading, use of APR, native IPv6 and SSL support, and many more. WWW: https://httpd.apache.org/