I'm starting a wiki, and the fact that websites (and wiki pages!) exist solely to compare different wiki solutions makes my head hurt.<p>My main goal is getting people to add content to the site, so my first take is to use the same software most people are likely to have already used via WikiPedia: MediaWiki. Does anyone have any opinions on this? Is there consensus about the one true wiki solution?
MediaWiki is the king of unrestricted wiki platforms. However, if you're looking to restrict access to certain portions of the wiki, or develop some sort of responsibility and/or permission structure, or add features such as forms and even embedded apps, I recommend TWiki. There are lots of plugins available, and there is plentiful documentation.
I'd personally go for Ikiwiki, just because it lets me ditch the browser for editing the wiki. I personally hate the embedded text controls in web pages, finding that they invariably stink. Ikiwiki stores the pages in a $SCM repository (eg, your pages are stored in Git or SVN or whatnot) so you can check them out and edit them.<p>Being able to check out the wiki from the repository backend that Ikiwiki uses and edit it with my editor of choice (Vim) is a huge win, I think.
I wrote one for Rails: <a href="http://dedawiki.dedasys.com" rel="nofollow">http://dedawiki.dedasys.com</a> and it's open source.<p>It's not as fancy as the mediawiki one, but it's easy to customize - observant people will notice that it shares a lot with another site of mine, <a href="http://www.squeezedbooks.com" rel="nofollow">http://www.squeezedbooks.com</a>
I think <a href="http://wikinvest.com" rel="nofollow">http://wikinvest.com</a> uses a heavily modified MediaWiki. If you're happy with PHP, it's a solid choice.
I use pbwiki; free personal version; has all the features i need; wysiwyg, data backup, fairly simple UI<p>I really like versionate -- but it is still missing some critical features -- I am keeping a close eye on it and hope they eventually do the needed upgrades.