SAN FRANCISCO -- Google opened its Google+ social network to the world on Tuesday, dropping the need for an invitation to join the Internet giant's rival to Facebook.

"For the past 12 weeks we've been in field trial, and during that time we've listened and learned a great deal," Google senior vice president of engineering Vic Gundotra said in a blog post.

"We're nowhere near done, but with the improvements we've made so far we're ready to move from field trial to beta... Anyone can visit google.com/+, join the project and connect with the people they care about."

The announcement came as part of a list of the 10 latest improvements Google is making to the social network it launched in an invitation-only test format on June 28.

Enhancements to Google+ included letting members take part in video-chat "Hangouts" using camera-enabled smartphones or tablet computers, or broadcast video presentations to groups of watchers using "Hangouts On Air."

Google said it has also woven its Internet search expertise into the social network by adding a query box.

"Google+ is still in its infancy, of course, but we're more excited than ever to bring the nuance and richness of real-life sharing to software," Gundotra said.

"Over the next day we'll be rolling out all of these features globally," he said.