Version 4 of Pixar

A company specializing in computer graphics and graphical effects for the movie industry. Uses Tcl internally. See for example

Michael B. Johnson's Keynote speech [L1 ] at the Sixth Annual Tcl/Tk Conference.
Check out Michael's Wave's World thesis at http://xenia.media.mit.edu/~wave/ for Tcl related items
Mark Harrison recently posted on the comp.lang.tcl newsgroup that he is employed by this company now.
Check out Pixar's product pages, such as http://www.pixar.com/renderman/artist_tools/tools/alfred.html . Mark H. says See if you can spot the packed widgets.