It's a rare thing for Google to launch a product that benefits users of a Microsoft application, but that's just what the company has done with a new plugin designed for the many users of Outlook for email.
As detailed in this Google support page, it has released the Hangouts Plugin for Microsoft Outlook. The plugin allows users of Microsoft's popular email client to join, start or schedule a Google Hangout video session directly from Mail or Calendar. This system is supposed to be for Google Apps Business, Government or Education account users. It also requires Windows 7 or 8 (sorry, Vista PC owners) and Microsoft Outlook 2007, 2010 or 2013.
Once the Hangouts Plugin is downloaded and installed, users of Outlook should see two new buttons in the ribbon UI for Mail and Calendar for scheduled and unscheduled video calls.
A year ago, Microsoft announced it had added support for Google Talk to its Outlook.com web email service. That addition didn't make Google very happy. In fact the company's CEO Larry Page commented on the move during the company's I/O developer conference that same week, stating that Microsoft was "... inter-operating with us but not doing the reverse, which is really sad."