Space Clouds
The beta client is a client we use for testing new features and fixes before they are pushed to the live client, you can download it here
http://www.starsonata.com/dl/StarSonata_2_beta.exe

We keep it so that it can be used on live (liberty.starsonata.com) without any gamebreaking issues and it is often required to connect on test/livetest and use new features currently in development.
An important thing to note with beta client is that there are updates to it without any warnings, such updates are applied when you reconnect to the gameserver, they will not disconnect you but they may delay you reconnecting in the event of a disconnection.