Update 0.12 is now available as an opt-in Beta. Assuming no major problems, that version will become the default branch next week. To opt-in now, you just need to right-click on the game in your library, choose properties and go to the Betas tab. There is no password. Click here to see detailed instructions. If you're playing 0.10.3 (the current default build) there are quite a few changes. Non-spoiler list of the major changes since 0.10.3:

• Universe is now generated with a hybrid procedural/designed system. Some sectors are procedurally generated, some are designed, some are a combination.
• Bigger universe. There are now close to 100 star systems with over 300 planets, over half of which have some kind of anomaly or discovery.
• 130+ unique planetary anomalies/scan discoveries.
• New technologies.
• New weapons.
• New missions/side-quests.
• New achievements.
• Updated trade system.
• Experimental difficulty settings.
• Improved controller support.
• Players can now leave notes on the map by right-clicking.
• Improvements to the mission log including search function.
• Updates to localization.
• Various balances changes.
• Misc. bug fixes.