This is stooop (a Simple Tcl Only Object Oriented Programming scheme)
version 3.7. Stooop is implemented in a single sourceable file and
uses simple techniques to provide object orientation to the great Tcl
language.

Stooop supports single and multiple inheritance, data encapsulation
(all member data is public), dynamic binding, nested classes, object
copy, runtime type identification, optional runtime procedure and data
access checking as well as tracing.

As stooop is entirely written in Tcl, it will run on all Tcl supported
platforms, including Windows and the Macintosh, if you have Tcl
version 8.0 or 8.1.