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), pooled database connections, thread shared arrays, introspection commands, mass virtual hosting (no server restart), watchdog, control port and command mode, efficient handling of down-/uploads with async I/O, IPv4/IPv6
Core developers: Vlad Seryakov, Stephen Deasey, Zoran Vasiljevic, Gustaf Neumann
Source: https://github.com/naviserver-project/naviserver Info: https://wiki.tcl-lang.org/page/NaviServer Documentation: https://naviserver.sourceforge.io/n/toc.html