Open Cobalt Alpha is the first step in a long term project to make available to all people a free and open source platform for constructing, accessing, and sharing virtual workspaces for research and education. It's all done in Smalltalk.
The OpenCobalt project now moved forward to run on the latest Squeak 4.1. version. Read more.
There is also a new website online for sharing Cobalt worlds: http://cobaltworlds.com.