Simple Tcl-Only Object-Oriented Programming , or stooop, by Jean-Luc Fontaine, is an object system written in pure Tcl. stoop is also available as a module in Tcllib.
[http://core.tcl.tk/tcllib/doc/trunk/embedded/www/tcllib/files/modules/stooop/stooop.html%|%official tcllib reference]:
stooop, implemented in a single source-able file, uses simple techniques to provide object orientation to Tcl. Includes an HTML class browser and examples of a lifo and fifo stack. Consists of new and delete operators as well as a virtual operator. Object members are held in a global array bearing the class name.
stooop is the basis of various useful extensions/widgets , such as: