The International Review of Research in Open and Distance Learning (April - 2004) includes an interesting review entitled: "Educational wikis: features and selection criteria".
Thanks, three comments:
- Most wikis have for the user open html pages so they can paste any html/javscript they wish. Need a calendar? paste your favorit in it!
- Most Wikis have another approach to passwords: you become member of a group which has access to a certain level with the password of your group. (built inVersion control of pages recovers disaster editing, I love eWiki's simplicity.)
- eWiki in Moodle starts from the other side: you start with a environment with personal access and lots of built in functionality and there you organise "innercircle" groups.