The rules of the contest:

1. Must have an xmas theme
2. Submissions may be up to 1k (1024 bytes)
3. Submissions must consist of only js
4. Any and all externals are strictly forbidden
5. Must work on current browsers versions (ch, o, fx and sa)
6. The eval family is NOT allowed this time
7. You get canvas object, its context and body object for "free"
8. Your demo must work in the "html5" shim provided
9. Your demo must be submitted before xmas!

For more information the history of these sorts of contests, see the Wikipedia entry for Demoscene.