Apparently Microsoft has started the official beta program for Microsoft Office for Mac 2011, albeit not a public one. Selected and privileged few is getting email invitation which invites them to join the Office 2011 for Mac OS X beta program. The Office for Mac OS X 2011 beta program is available to join via Microsoft Connect.

To join the Office 2011 for Mac beta program, user has to accept the following non-disclosure agreement terms, which forbids beta testers from publicizing the beta:

The Office for Mac 2011 beta is closed to the public, which means ALL Office 2011 tools and features are confidential and proprietary to Microsoft. By participating in the beta, you consent to a non-disclosure agreement which includes all forms of communication including print, broadcast, electronic, internet publications, social media networking sites, blogs, and verbal disclosure. The NDA will not lift until the product is public later this year. We will update on timing closer to the date.

Office for Mac 2011 includes applications such as Word, Excel, PowerPoint and Outlook. The Outlook 2011 for Mac will be the first time Outlook, with Mac OS X inspired theme ribbon, is available on Mac OS X platform, replacing Entourage. In addition, there will be new co-authoring tools, and integration with Office Web Apps.

For people who does not receive the invite to join Office for Mac 2011 Beta program, fear not, as the various beta builds of Office 2011 for Mac is now leaked to the Internet for free download, together with the product keys necessary to install the software product. The latest leaked Office for Mac 2011 is of beta 5, with build version Users who interested can download the Office for Mac 2011 Beta 5 (100709).