Google released a new client library which exposes almost all of the OpenSocial v0.8 JavaScript APIs in native ActionScript 3 for Flash and Flex gadget developers. The library provides an event-driven development model that is prevalent in the ActionScript community, a FlexUnit-based testing framework, and samples for both Flash and Flex environments. We hope the library will ease the learning curve for ActionScript developers and shorten the development cycle.

More info: ActionScript Client Library