Horowitz said that Google has no immediate plans to release as open source any of the proprietary code it has been developing for Google+, but that it has developed the site for data portability and compliance with open standards.

Although the only applications active on Google+ currently are some games made by developers who got exclusive early access to the site platform, Horowitz acknowledged that individual spammers are nonetheless kicking the site's tires.

However, he said that Google+'s Circles feature for sharing and controlling access to content makes the site inherently unattractive to end users who spam others.

Google is also betting that Facebook users will find Circles to be a better, simpler way of sharing content, but Facebook on Tuesday announced , to make it clearer to users who sees what they post.

Horowitz claimed Google deserves some credit for Facebook's changes, saying that "what they did was familiar and good for users."