0.0.10a was a version of Classic released on May 17, 2009, at 11:53 UTC. This version was originally going to be released to the public, but had a bug which made it unplayable, and so it was replaced by 0.0.11a after only four minutes.[1]
Additions
General
F10 + Esc + Alt unhooks the mouse and pauses the game.
Changes
Performance
Stability increase.
Building
Right click switches between placing and destroying modes.
References
↑"lwjgl IRC logs" , May 17, 2009. "<Notch_> 0.0.10a should be up now"