Install itcl3 by entering the following commands in the terminal:
sudo apt update sudo apt install itcl3
Description:
[incr Tcl] OOP extension for Tcl - run-time files
[incr Tcl] (or itcl) is a popular object-oriented extension for the embeddable Tcl scripting language. The name is a play on C++, and itcl has a similar object model, including multiple inheritance and public and private classes and variables. Unlike most OOP extensions to Tcl, itcl is written in C for speed. . This package contains everything you need to run itcl scripts and itcl-enabled apps.
Homepage: http://incrtcl.sourceforge.net/
Version: 3.4.3-2
Section: universe/libs