There hasn't been a whole lot of space sim news coming out of E3 this week, but after a ten-year hiatus, the LAN party favorite OpenParsec is under active development again. The game is sometimes described as "Quake in space," where deathmatch gameplay takes place within a single solar system. This new public release, the first since 2003, is playable on Windows, Mac and Linux. You can grab v0.20 here. Thanks to CrazySpence for pointing this out. Spence also put together the gameplay video embedded below.
Parsec is going to introduce you to a whole new universe. The core of Parsec will be a network of gameservers each responsible for a single galaxy comprised of several solar systems. All gameservers will be registered at the central Parsec masterserver from where you can select a specific gameserver for playing.
The basic unit of game play is a single solar system but you can jump from system to system as you like. There are no game sessions that have to be started explicitly. You can seamlessly join and unjoin a gameserver at any time. But beware! While you are peacefully exploring the universe everyone else will try to shoot you down to advance their position in the roster of all-time Parsec legends. If you want to become a legend yourself, you will have to eliminate a lot of other spacecraft and still prevail to collect the honor.