From the README:

   OTcl, short for MIT Object Tcl, is an extension to Tcl/Tk for
   object-oriented programming. It shouldn't be confused with the IXI
   Object Tcl extension by Dean Sheenan. (Sorry, but we both like the
   name and have been using it for a while.)

   Some of OTcl's features as compared to alternatives are:
     * designed to be dynamically extensible, like Tcl, from the ground
       up
     * builds on Tcl syntax and concepts rather than importing another
       language
     * compact yet powerful object programming system (draws on CLOS,
       Smalltalk, and Self)
     * fairly portable implementation (2000 lines of C, without core
       hacks)

   OTcl was presented at the Tcl/Tk Workshop '95. It constitutes a
   standalone release of a system that has been in use, embedded in the
   VuSystem, for two years. We made the release public (with free use,
   distribution and modification under the MIT license) to meet the
   demand for object-oriented programming in Tcl.

-Oscar <obonilla@fisicc-ufm.edu>