Adobe has partnered with one of the most popular social networking Web sites, Facebook, to give developers a new set of tools to create applications.

The applications will use Adobe's Flash platform and the new ActionScript 3 Client Library for Facebook the two companies developed together. The client library is a free open source programming language that supports Facebook application programming interfaces (APIs) including Facebook Connect.

Adrian Ludwig, Adobe's group manager for platforms, told Macworld that the companies will release the library and then gather feedback from developers. The libraries will be updated, adding functionality based on that feedback, allowing developers to make better applications.

The number and types of developers using Flash is increasing all the time. Some of the developers are focused on Flash, while others are coming from more traditional segments of the market.

"We are seeing that it's becoming quite easy for traditional developers to start using Flash," said Ludwig. "That's quite a change from where it was five to eight years ago when Flash was focused on animation."

Adobe said that Flash Player 9 has 98 per cent penetration, meaning that 98 per cent of all Internet connected computers have the application installed. The company did a study two months after the release of Flash Player 10 and found 55 percent penetration. While not released yet, Ludwig said he expects the latest adoption rate for Flash Player 10 to top 80 percent.

Those numbers give Flash Player 10 the fastest adoption rate of any version of Flash Player, according to Adobe.

Writing Facebook applications in Flash is not new. In fact, 12 of top 20 apps on Facebook use Flash. However, the new tools should make it easier for developers in the future.

Adobe is making documentation, example applications and code available for download from its Web site. Flash 'evangelist' Daniel Dura has also posted up a tutorial video on how to build a Facebook application in Flash.