Open Source Options
- Alternatives to Stack Exchange - 
- Question2Answer - Godot engine uses it. . Looks pretty good - has vote and widgets; Wordpress integration. FB login.
Note that the 2 critical aspects of a Q&A site that OSE needs is:
- Upvoting - this distills wisdom to the top, with inherent limitation of answers being as good as the audience. With a quality and sizeable audience, as well as great management, this could fuel collective genius.
- Embedding of individual questions. Imagine embedding upvote capacity anywhere on the wiki or on the blog.