NaviServer
NaviServer, a high performance web server written in C and Tcl
...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