Ideogramic ApS was an entity that developed diagramming tools that tuned for use on electronic whiteboards and that operated using gestures much like on a Palm Pilot.
Major parts of the applications were implemented in Tcl/Tk.
Ideogramic's website is no more, but the Wayback Machine has several snapshots of it .
Cameron Laird, XMI and UML combine to drive product development , 2001 (dead link)