tachyon is a small fast web server, it is a work in progress but it is usable.

It is written in a language called "brace", a dialect of C I am developing
which translates into normal C. The source code is in the file "tachyon".

If you want to use tachyon, compile it using brace.
  http://sam.nipl.net/brace/

Configuration is by editing the source code.

You can redirect vhosts using symlinks, e.g:

  mkdir -p /www/test.com
  ln -s test.com /www/www.test.com

so, www.test.com will redirect to test.com

If the www-data user cannot access a file, it will redirect to https://whatever
(setup stunnel to connect to port 81 for https), and ask for basic auth. It
validates your user and password against the shadow file, uses seteuid to
become the user in question, and tries again to access the file.

POST, PUT and ranges are supported, CGI is not finished yet.