MOUNTAIN VIEW, USA: Google Inc has lured MySpace, the world's largest online social network, to its system courting independent software developers, raising its challenge to fast-growing Facebook.

Web search leader Google said on Thursday that MySpace will join its OpenSocial platform that allows developers to write programs across multiple social sites using one set of tools.

The tools, which will become available early Friday on the Web, will eliminate the need for small start-ups or even one-person shops to customize their programs for each site.

"OpenSocial is going to become the de facto standard (for developers) instantly out of the gates. It is going to have a reach of 200 million users, which is way bigger than anything else out there," Chris DeWolfe, chief executive and co-founder of MySpace, told reporters.

Google unveiled the system earlier this week and said it has already lured some of the biggest developers aligned with Facebook, which opened its site to outside applications in May in a move that has helped boost its user base to more than 48 million people.

Developers have created interactive programs that let users rank their friends, wage virtual food fights or compare and recommend music. Some of the applications are now used by millions of people and are already being sought out by advertisers.

"The Web has moved to its next stage," said Google CEO Eric Schmidt. "We always knew that the Web would be significantly social. We also always knew that it would be standard, open, and extensive, which is what this combination and the other activities today are showing."