Wiki software

[iago]

I need to create a wiki with some specific characteristics:
- User accounts required which can have varied access (basically, view or edit)
- Has to be modifyable, since some features are needed that I can easily write, but that wouldn't generally be included
- Fairly user friendly and intuitive, especially to edit, since the guy who'll be using this isn't really a computer guy. Doesn't require really difficult code.

If nothing else, I'm going to try out mediawiki, although I'm not sure what kind of user account access it allows. I figured I'd ask here first, just in case somebody else has experience with this.

[MyndFyre]

I love MediaWiki.  As long as you can write PHP you should be good.

[iago]

I've never tried modifying it, but it's not complicated? I've installed it and used it, and it's really nice.

[Chavo]

I use MediaWiki as well (as a module in Joomla).  It does everything you require and more.