However, when I hear 'Better Browser' I think better for the average IS and IT worker. Not even more powerful for the few hunderd experts in the world. And so I agree that would mean dropping some of the high-power concepts. Or perhaps, just hiding them from normal users. I muck with the source.
Categories are a way of dividing code into functional areas on a small scale.
In normal code development, I worry only about categories. Packages are a way of storing code into a repository. Parcels are the deployed version of a package. At deployment time, one wouldn't have the repository. So, during development I normally work only with the system browser and the Package browser.