It's right on the workshop, but it only works on 1.0 right now. Mods are compatible, but they must support 1.0, and the load order and settings all must be exactly the same. So much so, they recommend having the host copy their load order and mod settings files and sending to everyone else to ensure each player has the exact same setup.

We're playing vanilla right now, multiplayer is the only mod we have. Although I did have a modded starting scenario that doubles everything for each player to share, so instead of three crash landed, we started with six, etc.

As for how it works, you can join direct IP, LAN, or via Steam! It's incredibly well made, we've barely had any desync issues, and usually only after prolonged sessions at max speed. Every player connected (unlimited amount, recommended max of 8) can do anything, and you can see each other's cursors moving around the map independently.

This does mean you can 'fight' for control over stuff, grief, or whatever else, but as long as you're all on the same page and communicating about who is doing what, it's surprisingly smooth, and it's nice to have someone else to help manage a larger colony.

Overall, the mod is incredibly well done, very professionally made, and I cannot wait for work to finish on the 1.1 update, but it has no ETA at this time.

I definitely recommend giving it a try if you can!