From Starbounder - Starbound Wiki
Perturbed Koala was the initial public beta release, released on December 4th, 2013. Prior to entering beta, the game was not publically available and had only been played by the developers, their friends, family and a few contributors.
Read the "Alpha" version article for an overview of early development.
Read the "Pre-Beta" version article for an overview of early-beta development.
It was announced and FAQ were detailed on the developer blog shortly before release.