Tk related software I have been involved:

TkDND: A drag & drop package for Tk. http://www.iit.demokritos.gr/~petasis/Tcl/index.html, http://sourceforge.net/projects/tkdnd

Tk Toolbar: Facility for creating dockable toolbars. http://www.iit.demokritos.gr/~petasis/Tcl/index.html

Ellogon: An natural language processing platform http://www.iit.demokritos.gr/~petasis/Ellogon, http://www.iit.demokritos.gr/skel/Ellogon