X-Plane 11

X-Plane 11 is currently undergoing public beta testing. This gives users access to an early preview release aimed at finding and fixing bugs in the software prior to the “final” release. Because of the high probability of encountering bugs in the beta, all purchases at this time also include access to the X-Plane 10 digital download as well.

http://www.x-plane.com/desktop/buy-it/