Apache HTTP Server - Apache httpd has been the most popular web server on the Internet since April 1996
TrustLeap G-WAN Web Server - TrustLeap G-WAN Web Server is a super-fast web server available for the Windows and Linux operating systems.
Apache Tomcat - An open source software implementation of the Java Servlet and JavaServer Pages technologies
lighttpd - A secure, fast, compliant, and very flexible web-server that has been optimized for high-performance environments
LiteSpeed Web Server - LiteSpeed Web Server (LSWS) is a high-performance Apache drop-in replacement.
Baby Web Server - Baby Web Server is the name of a multithreaded web server that is called to be one of the best alternatives to the MS IIS and even Apache HTTP Server.