Rob Med should give the answer. However, as far as I know, the architecture of Hal 6 is completely different than Hal 5: the new plugins are kept as separate files but are then inserted "on the fly" in specific points of the main brain, which is a common software tecnique, usually known as "user exit".
The Alice plugin was instead an alternative brain (you must use it as a replacement of the standard brain) and I believe you can't install it "as is" as a Hal 6 plugin. It should require some work to be adapted to the new architecture. Furthermore, Hal 5 used a lot of scattered files to store all the things he learns, while Hal 6 uses a more advanced SQL database.
I already suggested Rob to create two separate Web pages for the two different plugin areas, just to avoid these misunderstandings among users. I hope he will find the time to do it.
