Last Friday, we promised more information, so here it is. We've purposely been keeping kind of quiet about Platform on the site in order to give all the new applications and functionality—on our side and on the developers' side—time to breathe and grow virally. Now that we've seen a week of activity, it's time to give you the full story on Platform and what it means for you.

When we made changes to the site back in April, we broke up the menus to differentiate between the applications people use on Facebook and the core of the site. Applications are things like Photos, Notes, Groups and Events. They live in the left hand menu and they use different parts of the core, which tend to live in the top menu—things like Facebook profiles and News Feed. But most importantly, applications use the real connections people have to help them share information more efficiently.

For example, the Facebook Photos application is actually the #1 most trafficked photo application on the entire web because it uses people's real connections—what we call the social graph—to help people efficiently share their photos. Facebook has this graph of increasingly powerful connections that people use to communicate.

We started working on Platform a little more than a year ago. Since then we've taken Platform out of beta, written FQL(Facebook Query Language), and various other tools for developers, and now we're ready for the next step. With this evolution of Facebook Platform, we've made it so that any developer can build the same applications that we can. And by that, we mean that they can integrate their application into Facebook—into the social graph—the same way that our applications like Photos and Notes are integrated.

You'll see applications integrating into Facebook in a lot of familiar ways. Applications can have a box on the profile. They may also have an item in the profile actions menu (below your profile picture). They can also have a link in the profile drop-down menu and put stories in Mini-Feed.

That's just profile integration though. Applications can also have a presence in the left hand menu, and that link can take you to whole pages that are generated within the Facebook site. These pages are in many ways the part of Platform that really enables developers to build full applications for Facebook. Applications can have anything they want on these home pages, and they can have as many pages like them as they want. It's not just a widget; it's a full application.

Since there will be a lot of applications, you will have the choice of adding and removing any applications you like. You can add new ones and even remove ours if you like. Wherever applications are displayed in some order, we try to let you reorder them. This means that you can reorder the boxes in your profile and the applications in your left hand menu in any way you want.

Maintaining the user experience is important, so we've made it so that you have to click to activate any flash object before it can start playing. This will prevent animations or videos or music from playing when a profile loads.

It's important to remember that simply seeing an application is not the same as interacting with it or granting it the ability to see your information. You will have to opt-in to any application in order for it to access your information or be put on your profile. Also, please note that we never sell your information or expose your contact information. You can manage your applications—ones you've added to your account, used on other sites or on your desktop—and use granular privacy controls for other applications in the "Applications" section of the Privacy page. If you see an application that you think is offensive or worrisome, you can report it, block it from ever interacting with your profile or information, or do both.

You can get a taste of how this all works by adding our Video application to your profile, or looking for an "add" link when you discover a new application on your friends' profile or within your News Feed.


Katie is Facebook's Director of Product.