Space-based architecture?

Question

One chapter in Pragmatic Programmer recommends looking at a blackboard/space-based architecture + a rules engine as a more flexible alternative to a traditional workflow system.

Answer 1

Gigaspaces is a successful commercial implementation of JavaSpaces -- so, I wouldn't say JavaSpaces is dead.

You might take a look at Java Shared Data Toolkit (also this article) to see if it meets your requirements.