Reactive Extensions (Rx) has been open sourced by Microsoft Open Technologies. This increases the chances that it will be available with Mono soon as well.
Rx is a library for composing asynchronous and event-based programs using observable sequences and LINQ-style query operators. Rx .NET 2.0 shipped in August with several new features. The sources are now made available under the Apache license and the project is accepting contributions from the community.
Reactions from developers have been mostly positive. Almost immediately after the announcement, mono-reactive, a project that aimed to bring Rx features to Mono has been abandoned by it’s project owner Atsushi Eno -
I happily announce that I'm not going to work on this code base anymore now that Microsoft has open-sourced Reactive Extensions in Apache license.. Thank you Microsoft!
Miguel De Icaza tweeted -
Amazing, as part of the opening of Rx, Microsoft also open sourced their IL to JavaScript compiler
Reactive Extensions has been useful in several projects – some already highlighted are GitHub for Windows and Netflix. However the reactive style of programming is also useful for real-world programming such as working with Kinect and making monsters come alive.
You can learn more about Reactive Extensions on MSDN and on InfoQ. You can also read this free online book “IntroToRx”.