Modules group 1 or more files together. They are also the smallest unit of code that can be sandboxed separately.
Modules have a namespace that is local to the world.
Users can request a namespace for all their code, which doesn't necessarily have to match their username, but must be globally unique, like a twitter address.
A module by 'nathanael' could have this namespace, for example.
nathanael.forestadventures.sleepingking
Modules can contain subdirectories, which always mirror the namespace packages.
They can contain CSS files, javascript/coffeescript files, and weaver files.
Hooks
Extensibility is important, especially in town centers.
Every code file could define a 'register' function that returns a dictionary of 'event'->'handlers'. (multiple handlers can be defined for one event, if needed).
