This is Tcl version 8.6, an embeddable tool command language.

Tcl (Tool Command Language) is a very powerful but easy to learn dynamic
programming language, suitable for a very wide range of uses, including web
and desktop applications, networking, administration, testing and many more.
Open source and business-friendly, Tcl is a mature yet evolving language that
is truly cross platform, easily deployed and highly extensible.

A full set of manual pages is also provided with this port.

WWW: https://www.tcl.tk/