It's a very interesting paper
Leaving this here so that one can cry how advanced IDEs were on those days and what we have lost.
Kalman Reti, the Last Symbolics Developer, Speaks of Lisp Machines: http://www.loper-os.org/?p=932
Additionally
http://www.sts.tu-harburg.de/~r.f.moeller/symbolics-info/sym...