AOLserver is America Online's Open-Source Web server. AOLserver is the backbone of the largest and busiest production environments in the world. AOLserver is a multithreaded, Tcl-enabled web server used for large scale, dynamic web sites. AOLserver is extendable with both C and Tcl APIs that expose core functions and provide primitives for accessing the database. AOLserver also provides optional CGI support, although the C and Tcl APIs are more powerful, offer superior performance, and are easier to use.