Avorion is now on kickstarter.
To quote the original (long dead) thread,
Just found this one today, its a spaceship sandbox, you start in a "pod" and have to mine, destroy, scavenge to find materials and money, with those you can build your actual ship, shipyards have seed-randomized construction and after that you can add blocks and weapons individually where you want to. The map is huge and it supports multiplayer, so far iv played only around 10 minutes so i dont know much yet, but it haves lots of potential for sure. Its not released yet and the download is around 100 mb. It may not have the DIY of corneroids but its in a much better state at the moment.
Website: http://www.avorion.net/
Kickstarter:
Avorion LinkDemo:
Demo HereFactions are randomly generated and keep a consistent, randomly determined, ship style on randomly generated ships.
The kickstarter description is as follows,
"Avorion is a procedurally generated sci-fi sandbox where you start the game at the edge of the galaxy and must find your way to its core.
While you can build your own ships, Avorion focuses on actually flying around in your ship, exploring and fighting. Think of your ship more as a character in an RPG, not just a vehicle.
The galaxy gets more hostile, but also more rewarding the closer you get to its core.
Avorion is about you. It's designed so that you can play in your personal way, as a mercenary, freighter captain, admiral, scavenger or pirate. You decide!
Avorion is already very far in development. Konstantin developed the game for four years next to our studies at university."
I tried out the demo and it seems a bit further along then when I tried it a few years back. I went ahead and tossed about $30 on it as it seems like it has some good potential.