The launch of the Google+ social network casts a shadow over Google's previous efforts in this arena, including Orkut, Wave and Buzz, all of which still have active Web sites. For the most part Google+'s predecessors will coexist alongside the new social network as Google determines what works and what doesn't.

Google launched Orkut in 2004 after a failed bid to buy social-networking pioneer Friendster a year earlier. The site's popularity in the U.S. was quickly surpassed by a wave of interest in the site from young adults in Brazil (where more than half of Orkut users live) and India. One of the site's notable U.S. fans is Dom Sagolla, one of Twitter's first software developers, who at last year's Idea Festival in Louisville, Ky., called out Orkut as a social networking site with potential.

Google is in no hurry to pull the plug on Orkut. "Over time, we’ll determine what makes the most sense in terms of integrating these products," says a company spokesperson who asked not to be identified, adding that Google will continue to invest in the site, which has about 100 million active users worldwide.

Google introduced Wave in May 2009 as a site for merging e-mail, instant messaging, wikis and social networking. By August 2010 the company announced it was abandoning the effort, citing disappointing user adoption. Google has since turned over further development of Wave to the Apache Software Foundation. Google+, however, was developed from "the ground up" and doesn't include any components developed through Wave, the spokesperson says.

The Google Buzz social networking and messaging service launched in February 2010 and was quickly met with controversy over a lack of privacy protections. One of Buzz's key features was its ability to integrate social networking and messaging into Gmail, but this backfired in part because Buzz automatically shared Gmail contact information without first asking users' permission.

Google+ won't have any major impact on Buzz at launch, according to the company. Buzz users will still see a Buzz tab on their Google profile, and Buzz will continue working as it always has. "Over time, we’ll determine what makes the most sense in terms of integrating the products," the spokesperson says.

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