We're happy to announce the first official releases of Reactive Extensions v1.0 Stable and v1.1 Experimental:

More information will be available on Channel 9 and the Rx forums. Also check out the Rx homepage on MSDN Data Developer Center.

Together with the release of Rx v1.0 RTW and Rx v1.1 Experimental, we've brought back the Interactive Extensions (Ix) v1.1 Experimental:

Thanks for the continuous feedback we received over the last few years, building and growing Rx to what it has become today.