Social network MySpace is to open to third-party developers in order to let them build applications for the site.

The news, announced at the Web 2.0 conference in San Francisco, is being seen as a move to bring MySpace in line with rival site Facebook.

Facebook currently offers over 6000 applications, or widgets, that users can use on the site or embed into their profiles.

"The idea will be to allow outside developers to tightly integrate their applications into MySpace", Chris DeWolfe, the firm's CEO, told Reuters.

Facebook is a growing threat to MySpace's dominance as the world's largest social networking site but has a long way to go to catch up.

MySpace has more than 185 million registered users, compared to the 47 million who use Facebook.