MySpace, the world's largest online social network, yesterday announced it will open its platform to outside application developers in a bid to counter its close competitor Facebook, which launched the Facebook Platform months ago, leading to the creation of thousands of third party applications.

MySpace will open its platform broadly to outside developers in the coming months, according to MySpace’s CEO Chris DeWolfe, including a sandbox for two million beta users and the developer community where apps will be tested to make sure they are safe before deploying them to all users. Moreover, developers will generate advertising revenue from the applications they build for the site.

Although MySpace still claims the number one social networking spot, Facebook currently has a much faster growth rate, according to comScore Networks. The site has grown to 47 million active users today from 12 million in December, with over half of its active members returning to the site daily. We’ll have to wait and see if the MySpace platform can help the social networking giant lure back users lost to Facebook.