"It would have taken a lot more effort without OpenSocial," he added. "We can focus more on improving the user experience because we don't have to spend a lot of time retooling the application to work in different social networks."

However, Suhail Doshi, a student at Arizona State University who has built OpenSocial and Facebook applications, said the Facebook platform "wins hands down" in terms of functionality for development.

"This is sort of the nature when you've been around longer and you don't have to deal with meeting the demands of other big player social networks," Doshi said via e-mail. "There's a lot of gridlock and arguing over what should be in the specification and what should be prioritized. Facebook is allowed to iterate faster on theirs."

If Facebook holds out and an industry battle emerges over which platform will end up as the preferred standard, the key to win will be openness, minimal restrictions and strong APIs, said Doshi, who worked as an intern last summer at Slide, one of the biggest makers of applications for social networks.

"I would put my money on Facebook in the long run, but all the application developers are dependent on each network. Developing on OpenSocial is basically not putting all your eggs in one basket which is generally a good choice," Doshi said.