Perspecta Software was a start-up company founded in 1992 by John Ousterhout and Larry Rowe. Its first, and only, product was Perspecta Presents!, software for Unix workstations to create and display presentations. (Think PowerPoint!)
The product was Tcl/Tk-based, even though the canvas widget had not been released at the time. A similar widget to the canvas, called a spot widget, was embedded in the executable.
There appears to be some old information about Perspecta Presents! at http://www.rpi.edu/dept/rcs/packages/ppres/1.10/
Several Tcl'ers would be interested, for historical reasons, if the code could be released.