I’d love to see a blog engine that structurally encouraged editing old posts, much like a private wiki with an activity stream view. Readers would both be able to peruse articles/posts/entries either in order of creation or of last edit, but also view a timeline of edits, along with an easily-understood diff of the edits.

Yes, I know this is possible with github/jekyll-based blogs, but that’s not exactly friendly for a broad audience. I may build this for my own blog, since I’m more interested in building up a well-edited collection of essays than standard short-form blogging. Let me know in the comments what you think!