Forms

With Semantic MediaWiki and the Semantic Forms extension, you can easily create any content type in your wiki, and use a form-based interface to edit/modify the content.

For example, see this "Case Study" content type at the Creative Commons website: http://wiki.creativecommons.org/index.php?title=Case_Studies/Cory_Doctorow&action=formedit

Once the content is saved in the wiki, you'll no doubt want to have a way to present that content to users in a friendly way. Take a look at this "overview" page http://wiki.creativecommons.org/index.php?title=Case_Studies&action=edit