Concurrency (ActionScript Workers)
Create more responsive content by offloading tasks (high-latency operations and long-running computations) to background "workers" that run concurrently to leverage more machine resources.
Native 64-bit support
Experience improved performance of Flash Player content by taking advantage of native support for 64-bit operating systems and 64-bit web browsers on Linux®, Mac OS, and Windows®.
LZMA support for ByteArray
In addition to zlib compression of ByteArray, this compression type based on LZMA can be used to compress data inside a ByteArray.