ISBN — a conference dealing with text and document processing. Bob A. Morris, the host of this conference arranged a visit at Interleaf. I remember my foot walk across the Charles River Dam and the modern building of Interleaf not far north of the bridge. At that time Interleaf was porting their software from Unix to the MacIntosh — keeping their proprietary user interface they had developed in Lisp. I discussed with conference attendees whether it was a good idea to keep the proprietary user interface. My argument was that nobody at a computer works with only one application not even as a clerk on the so called main frames and hence is reluctant to deal with various interfaces.