This is the second alpha release for openHAB 2, released on May 25, 2015.
See the according milestone for issues that are part of this release.
The biggest features of this new alpha release are the stabilized compatibility layer and the long list of "new" bindings.
The release comprises the following downloads:
openhab-2.0.0.alpha2-runtime.zip
openhab-2.0.0.alpha2-addons.zip
openhab-2.0.0.alpha2-demo.zip