The MT Forums
Yes! Amazingly, people still read what we post over there. Also, you might stumble into some new mystery pictures or other goodies. Best place for MT news (not that we have any).
Hard Light Productions
Great guys. They host us. The focus of Freespace 2 activity on the web, they also host a ton of other great projects. Make sure to check it out, if you didn't arrive from there already.
If you're interested, this is a list of everyone currently working on the Machina Terra project, or helping us out with advice, comments, testing or other stuff.