boa(8) is a small, fast
Web server program written for
Unix and
Linux systems, and distributed under the
GPL.
The most interesting thing about boa is that, unlike Apache and most other Web servers, it does not fork to handle incoming connections. Instead, boa multiplexes among active connections. By thus avoiding the overhead of forking and maintaining child processes, it can serve static Web pages 25-50% faster than Apache.
The flip side is that boa does not support many of the features of Apache or other high-end Web servers. It does not support access control, nor server-side scripting, nor SSL. It serves static data in your favorite MIME type; and it can invoke CGI scripts. That's about it.
boa may be available in your Linux distribution; it can also be had from www.boa.org.