Well, there is a new announcement for OpenCroquet: soon! Even though OpenCroquet is based on Squeak Smalltalk that has some very old roots indeed, I still think that OpenCroquet may be a new paradigm shift - we will see.
Lisa Rein has set up a web site with Alan Kay's Video demos of OpenCroquet.
From the OpenCroquet web site: "a combination of open source computer software and network architecture that supports deep collaboration and resource sharing among large numbers of users".
BTW, the last 2 video files (numbers 5 and 6) contain the actual OpenCroquet demos - but the earlier files are also interesting.