The current development in Second Life is based on an earlier prototype that was developed in Croquet. Croquet is is a 3D network environment written in the programming language Squeak, a dialect of Smalltalk.
The Croquet environment exists on a computer network. Each participant interacts through the GUI on a networked machine.
The networked environment is implemented as a Croquet space. There is a separate virtual machine for each simultaneous participant in the environment; each of these machines provides a Croquet interface into the environment.
One virtual machine hosts the Croquet environment, provides a list of musical pieces to represent participants in the environment, renders MIDI into audio, and streams the audio results.
Another virtual machine hosts a music software environment for handling automatic music analysis and creation. That machine responds (via an http web server) to the flow of participants into and out of that space by computing new musical pieces based on the pieces representing the current inhabitants of that space. The machine returns musical results (via http) to the machine hosting the Croquet environment.
Each participant uses an additional virtual machine to connect to the shared Croquet space.
The GUI displays a landscape which is shared with other participants. Each participant is represented as an avatar in the shared landscape, and the participants can see each other's avatars. The GUI enables each participant to pilot their avatar around the landscape.
A menu provides a list from which the participant selects a piece of music to represent himself in the environment. There are three portals which each lead to a different shared music space. The participant pilots the avatar through a portal into a shared music space. Within that space they can see the other participants in that space, and through headphones (or speakers if they are isolated from the other participants) they hear the music currently playing in that space.
The participant can choose to linger in a particular shared space, in which his/her selection of a musical piece is incorporated into the musical piece playing in that space. Or the participant can pass back through the same portal through which he entered the shared space. This puts the participant's avatar back in the main area with the three portals. The participant can go on to explore the other music spaces. As pieces are created in the various shared musical spaces, those pieces can be added to the menu of available pieces.