On Sun, Aug 17, 2014 at 10:29 PM, Jos Dreesen <jos.dreesen at bluewin.ch> wrote:
The ETH Lilith had multiple, overlapping, multifont,
graphic-capable
windows in 1982.
Which was inspired by the Smalltalk environment on the Xerox Alto,
which had those features in 1976.
Though the Lilith was available for purchase, while the Alto generally was not.