When it comes to webservers on a linux based system you would 99% of the time think of Apache. Without a doubt Apache is the most popular free webserver and has plenty of resources on the web where you can seek help (http://httpd.apache.org) there are however a number of other free as well as commercial webservers available for other applications. Apache – http://httpd.apache.org Most well-known webserver software, with versions available for unix and windows. Currently has two stable releases 1.3.x and 2.0.x Boa – http://boa.org Can handle a huge amount of requests per second compared to other webservers. Configuration is very similar to that of apache Caudium – http://caudium.net Caudium has both stable and development releases, it has Pike and RXML support. Roxen – http://roxen.com/products/webserver Highly graphical webserver. Built around the Pike object orientated language. Thhtpd – http://acme.com/software/thttpd Flexible and occupies a small memory footprint. Basic server without high end capabilities. Tux / kHTTPd – http://kernel.org Webserver as a loadable kernel module. Unique. Zues – http://zues.com Considered the best enterprise level server. Users include ebay and red nose day. Huge amount of features. Price tag of £1100 1. Apache – Pre-fork; CGI; PHP; VHosts; Auth; No Throttling 2. Boa – Select; CGI; VHosts; Auth; Chroot; No Throttling 3. Caudium – Threads; CGI; PHP; VHosts; Auth; Chroot; No Throttling 4. Roxen – Threads; CGI; PHP; VHosts; Auth; Chroot; No Throttling 5. Thttpd – Select; CGI; Auth; Chroot; Throttling 6. Tux – Select; 7. Zues – CGI; PHP; ASP; VHosts; Auth; Throttling Pre-fork: Start a pool of processes which each handle multiple requests Threads: Use threads instead of processes/ Select: Use non-blocking I/O and the select() System call to handle multiple requests in a single process, single thread.