nginx - A high performance free open source web server powering busiest sites on the Internet.
Apache HTTP Server - Apache httpd has been the most popular web server on the Internet since April 1996
Cherokee - High-performance web server
lighttpd - A secure, fast, compliant, and very flexible web-server that has been optimized for high-performance environments
nanoweb - Nanoweb is an HTTP server written in PHP, designed to be small, secure, and extensible.
Google web toolkit - Google web toolkit is a development tool mostly used by world-class developers for building and optimizing complex browser-based applications.