Looking into a newlisp (distant?) future perhaps newlisp's contexts could be the basis for a concurrency model. I came across this blog:
http://home.comcast.net/~bc19191/blog/050119.html
discussing concurrency and lisp and got to thinking.
The current context system could be used to send off a light-weight concurrent process if it
was forbidden to/chose not to access other contexts or if inter-context contact was through
messages.
Perhaps in the future a fork of newlisp rewritten in erlang could be concurrent?
Just thinking out loud.
Nigel