It seems that Adobe is working towards removing some barriers to the adoption of its Flash technology. This may very well be due to pressure from potential competition such as Silverlight. From Adobe's site:

"...as part of Adobe’s ongoing commitment to enable Web innovation, Adobe will continue to open access to Adobe Flash technology, accelerating the deployment of content and rich Internet applications (RIAs). This work will include:

- Removing restrictions on use of the SWF and FLV/F4V specifications
- Publishing the device porting layer APIs for Adobe Flash Player
- Publishing the Adobe Flash® Cast™ protocol and the AMF protocol for robust data services
- Removing licensing fees - making next major releases of Adobe Flash Player and Adobe AIR for devices free"

Now, all it says is that the licensing fees will be removed. I am not sure what part of this will actually be free and open source (maybe none), but we'll have to wait and see.