Due to an increasing number of problem users/spammers you now have to login at the wiki to be able to edit pages.
This is done to minimize the time I need to spend making sure noone does any damage at the wiki (links to porn sites or ebay, adding html and stupid comments have been seen so far).

It's also worth mentioning that registration is really painless. You don't even need to validate your account. Just create it and start editing at your heart's desire.

It's definitely the smarter way to go. I was confused why you guys hadn't done that in the beginning. They bombarded the xiph wiki poor bastards.