WPMU dev – is this plugin a copy of another one?

I am creating a QA site for medical students (think localized stackoverflow).
I’ve been searching for solutions and found the Q&A plugin from WPMU DEV ( https://premium.wpmudev.org/project/qa-wordpress-questions-and-answers-plugin/ ) but due to their reputation (http://alisothegeek.com/2011/06/wpmu-dev-copyright-infringement-looking-at-the-code/) I am unsure if this plugin is also a copy of another that is accessible elswhere.

I would rather get the plugin from the original source (to reward the actual author and get official support} than from a re-seller if possible.

Is the plugin available elsewhere or is it an original creation from WPMU dev?

Thanks for any input,
Marek

PS: there is also the wiki plugin https://premium.wpmudev.org/project/wordpress-wiki/ – a copy or not?