This terrific video of the Alternate Reality Kit was made at Xerox PARC in 1987. So, of course, it’s not actually Brie, but it does give a lot of the feel of what we’re going for. There are a few UI differences and the ARK is only 2D, but the main thing is that Brie is synchronously collaborative, and therefore eminently shareable.
Another related thing (without a cool video) was PARC’s Thing Lab.
My thinking is that we need to get a minimal, clean, and solid Hedgehog out as soon as possible, rather than cramming it full of more code and half-finished, un-integrated demos. So rewriting Brie for Hedgehog persistence can be done as an update later, and the above will be all there is to see of Brie for a while.
We never did have time to get Brie into our interim Dormouse version of Croquet, but like the ARK, it is somewhat suggestive of the concept. In Dormouse, you can build up your own world by interactively adding to and arranging stuff you find in other worlds. (What kind of world can you build? One kind is the meta-medium 3D wikis described here and here.) Dormouse has some very limited hard-coded Brie-like behavior transfer ability, in which you can reach into a (e.g., found) object and pull out its material or its sound, and then transfer that material or sound to another object. For example, you can put one character’s clothes onto another. The distinction with real Brie is that any such behaviors can be pulled out (e.g., that the object can jump, or that this jump is invoked by clicking on the object) rather than just those predefined behaviors (like material texturing or sound) that some programmer predefines as being able to be pulled out and recombined.