[dkf] has been doing [OO], too - here [http://www.man.ac.uk/~zzcgudf/tcl/oo2.tcl] is his pure-Tcl approach with the following features:
   * requires Tcl 8.5 ([dict])
   * about 16KB of size
   * prototype-based, but which has a class-based face built on top
   * in an earlier phase, presented at the 2004 Tcl convention

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