AspectJ is an AOP language based on Java. It's under active development of Xerox' PARC.
In the current state AspectJ is a research item and freely available. I think we need to discuss the use of AspectJ or AOP.
There are many questions:
-- MattAlbrecht (26-Aug-1999)
I feel that Aspects are indeed the next step in programming paradigms, and it is well worth the effort to see the development in the language and ideology behind Aspects. However, I also feel that the idea and language are too immature for a robust operating system. Perhaps when the language becomes stable, we can attempt a "AspectJOS". (The last change to AspectJ redid how the language works - I expect these kinds of changes to happen somewhat often at the beginning of its life).