OpenMeeting is an open-source and independent alternative for Google Hangouts. It allows video/audio conference, collaborative editing, screen sharing, instant messaging, etc. OpenMeeting community provides plugins for integrating to common platforms like Moodle, Sakai, Jira, Joomla, Bitrix, Confluence, SugarCRM, Redmine. Unfortunately, the Drupal plugin for open meetings is not open-source.
A good news is, OpenMeeting provides a SOAP API for integrating OpenMeeting with other platforms.
I will explain how to create a new conference via OpenMeeting's SOAP API.