NaviServer
NaviServer, a high performance web server written in C and Tcl
NaviServer is an extensible web server suited to create scalable websites and services. Originally based on AOLserver (http://www.aolserver.com), the ongoing development is done independently under Mozilla Public License by a core group of people that use it for their businesses and by other supporters.
Features: High performance multi-threaded architecture, massively scalable and extensible, many modules, dynamic scripted pages (ADP), caching functions (static files, Tcl byte code, chunks...