XS-HTTPD is a WWW server that has the following features:

- It is pronounced as "access-HTTP-daemon"
- It is SMALL (very small in fact: a factor two to three smaller than
  normal servers on disk and in memory)
- It is FAST (because it is so small and does not do unnecessary things)
- Uses very little CPU time
- Configurable (configuration compiled in to make it small, but largely
  overridable on the command line)
- Runs user CGI binaries under their own user ID
- Gets users' pages under their own user ID, allowing them to really
  have protected pages (using the built-in authentication mechanism)
- Does not fork for every connection (has a fixed number of servers),
  only to replace a lost server (in case of timeouts).
- Comes with some other useful programs
- Offers Server-Side Includes for many common tasks, including built-in
  page counters (text or graphical)
- Supports PHP and other interpreted file formats
- Supports automatic decompression to save diskspace and bandwidth
- Serves SSL (https) and http connections through the same daemon
- Full support for IPv6

WWW: http://www.stack.nl/xs-httpd/