A web server commonly known as HTTP server or application server is a program that serves content using the HTTP protocol. This content is generally in the form of HTML documents, images, and other web resources, but can include any type of file. The content served by the web server can be pre-existing (static content) or generated on the fly (dynamic content).
1. Apache web server – the HTTP web server: Apache Software Foundation developed the free and open source web server and can be installed and made to work on almost all operating systems including Linux, Unix, Windows, FreeBSD, Mac OS X and more. Almost, 60% of the web server machines run the Apache web server
2. Apache Tomcat: Apache Tomcat is free and open source web server that can run on different operating systems like Linux, Unix, Windows, Mac OS X, Free BSD. It was developed to support servlets and JSP scripts. It can serve as a standalone server.
3. Lighttpd: Lighttpd is a free web server distributed with the FreeBSD operating system. This open source web server is fast, secure and consumes much less CPU power. Lighttpd can also run on Windows, Mac OS X, Linux and Solaris operating systems.
4. Jigsaw: Jigsaw (W3C’s Server) is introduced by the World Wide Web Consortium. It is open source and free and can run on various platforms like Linux, Unix, Windows, Mac OS X Free BSD etc. Jigsaw is written in Java thus can run CGI scripts and PHP programs.