muhttpd is a simple but complete web server written in portable ANSI C, supporting logging, CGI scripts, MIME type based handlers, and HTTPS. It has been tested on various Unix environments on 32-bit, 64-bit, little endian and big endian systems.
A free and portable Common Lisp Webserver.
Portable AllegroServe is a variant of AllegroServe(tm) with an explicit emphasis on portability between Lispsystems and Operating Systems. You can find the original AllegroServe at https://github.com/franzinc/aserve
The best way to install Portable AllegroServe is through Quicklisp (http://quicklisp.org/).