MOUNTAIN VIEW, CALIF. — Internet search company Google Inc. is joining forces with MySpace to make it easier to create programs for the biggest social networking site, a move that draws sharp battle lines with their respective rivals, Microsoft Corp. and Facebook Inc.
Stealing some thunder from fast-growing Facebook, Google and MySpace said Thursday that software developers could now use a common technology standard Google had created to build features for MySpace users.
Called OpenSocial, the standard also can be used on other participating social networking sites, such as LinkedIn and Friendster.
The standard is a boon for small outfits, which no longer need to customize their programs for each site. A developer could, for example, create a software widget that would let MySpace users book travel plans, and put that widget on other participating sites as well.
The alliance is a counterpunch to the momentum of fast-growing Facebook, which has been fueled by thousands of new programs added by developers since the Palo Alto-based social network opened up its site in May.
It also shows how the social-networking world is commanding the attention of far bigger companies. The deal comes just a week after Mountain View, Calif.-based Google lost out to archrival Microsoft for the right to invest in Facebook, and it now pits two of the largest five U.S. companies by market value squarely against each other on yet another front.
"Everybody is lining up, picking sides and buying weapons," analyst Rob Enderle said. "This is going to be bloody for a while. The battle for the social networking space is going to be hard fought."
MySpace Chief Executive Chris DeWolfe predicted that OpenSocial would become the "de facto standard for developing applications instantly out of the gates."
Google said all social networks had been invited to take part in the OpenSocial network. "Nobody is excluded," Chief Executive Eric Schmidt said.
But a Facebook spokeswoman said the company had not been briefed.
"When we have had a chance to understand the technology, then Facebook will evaluate participation relative to the benefits to its 50 million users and 100,000 platform developers," Brandee Barker said.
Another popular social network, Bebo.com, will participate in OpenSocial along with Hi5 Networks Inc., LinkedIn Corp., Ning Inc. and Friendster Inc., as well as Salesforce.com Inc. and Oracle Corp., both of which sell software to businesses.
The addition of so many major players could put pressure on Facebook to join the coalition. The OpenSocial network is expected to reach more than 200 million Web users.
OpenSocial is unlikely to have any immediate effect on Facebook's popularity, but it could boost social networks left in the digital dust by MySpace and Facebook, including Google-run Orkut, which is popular in Brazil and India but never gained traction in the United States.
Google also benefits in another way: As developers build more programs helping social networks gain more users, it is likely to sell more ads.
Talks with Santa Monica-based MySpace, which has 110 million users, kicked off about a year ago, Schmidt said. In August 2006, Google struck a $900-million advertising partnership with MySpace and other websites owned by News Corp.'s Fox Interactive Media. At the time, Google said it was drawn to MySpace's rapid growth.
Google announced the OpenSocial platform Tuesday, just days after losing out to Microsoft in the blockbuster deal that valued 3-year-old Facebook at $15 billion.
Facebook has vaulted over rivals to become the social network with the greatest momentum, adding about 1 million users a week. A flood of free software programs -- to join causes, book travel, turn your friends into virtual zombies -- has been a hit with users. Millions of users signed up for the most popular programs in a matter of weeks.
But Facebook's approach is in stark contrast to the one taken by Google and its partners. Facebook requires developers to use its proprietary software language to write programs. With Google's OpenSocial, developers now have the option of using a common language for many social networks. The biggest Facebook developers, including Slide, RockYou, iLike and Flixter, have all said they plan to do so.
Facebook also had endeared itself to developers by allowing them to advertise on its pages, while MySpace has not. MySpace executives have said change is coming, including ad-sharing for some programmers.
A question unanswered by Thursday's events was whether the financial terms of OpenSocial programs would stay the same from one site to another. That has yet to be sorted out, people familiar with the process said.