A server process (daemon) that serves up hypertext (html) documents via the hypertext transfer protocol. (Also images and other embedded files.) Also known by many as a web-server.

Some common httpd's are:
  • Apache - The most common web-server on the Internet. Runs on Unix systems mostly, but has ports to other platforms. An open source web server distrubuted under a free licence.
  • IIS - Microsoft's Internet Information Server. Runs on Windows NT.
  • PWS - Microsoft's Personal Web Server. Runs on Windows 95/98. As the name might suggest, should be used only for testing or for personal web serving as it's not very powerful and is lacking in functionality. Comes "free" (as in beer) with Windows