According to the AllFacebook blog, Facebook just announced that they’re taking on the OpenSocial movement by allowing other players to use their platform architecture to build social media sites.

“Now we also want to share the benefits of our work by enabling other social sites to use our platform architecture as a model. In fact, we’ll even license the Facebook Platform methods and tags to other platforms. Of course, Facebook Platform will continue to evolve, but by enabling other social sites to use what we’ve learned, everyone wins — users get a better experience around the web, developers get access to new audiences, and social sites get more applications.

This is just another step toward the vision of easy, open sharing of information. We look forward to supporting other social sites as they release their own platforms, and look forward most of all to the added benefit for developers and users.

You can find more information here and additional technical details here.

What it means: With that move, Facebook hopes their architecture will become the defacto standard for social media. It’s Beta vs. VHS all over again! As OpenSocial is still in its infancy (even though many large players have embraced the standard), this could be a disruptive move by Facebook. Smaller social sites who had not yet joined the movement might reconsider. It will be interesting to see who will use Facebook’s architecture.

Update: it looks like Bebo will be using the Facebook architecture!