Roxen is a kick-ass webserver put together by the lads at Idonex. It's GNU, and is written in Pike which is an interpreted scripting language with syntax very like C. Roxen has a vast feature-set, including the use of RXML which is a scripting language built into regular HTML code and allows you to generate dynamic content quickly and easily. Roxen has modules for generating graphics, SQL database queries and all sorts of other shit on the fly.