The public test server is open — log in and play right now. The server is updated to version 0.3.510.

 
Highlights since the last announcement: faction caravans (escort or raid) with a caravan board in the PDA, construction and personal camps, the faction Guard system, non-combat quest paths, faction ranks and reputation-driven prices, co-op faction play, knockouts and Perception-based ranged accuracy, the new armor-part slot, reworked abilities and detailed skill descriptions, weather that affects movement and visibility with a body-temperature HUD, no more permanent item loss on death, character management in the PDA — and much more.
 
How to join: log in on the site and open the testing section — server status and downloads (installer or portable) live there. Guides for every system are in the knowledge base.

Found a bug or have feedback? Post it in the testing section — it has a built-in tracker. Every report helps. See you on the Last Frontier!