Microsoft gives U.S. college students the Office 365 for up to six months free of charge.

The offer is part of Microsoft's Office 365 University four-year subscription plan that lets eligible university and college students install Office 2013 on up to two PCs and Macs, as well as install Office Mobile Apps on two smartphones running Windows Phone 7.5 or later. The plan's price is $79.99.

Students will also receive an additional 20GB of storage space on SkyDrive, Microsoft's cloud-based service, plus the usual 7GB all customers are allotted.

If an eligible student shares the Offer on Facebook they will be eligible for an additional consecutive three-month Microsoft Office 365 University subscription. To share via Facebook, the user must visit the Offer Site enter and submit their qualifying .edu email address, then click the share link, log into their Facebook account and share the Offer. After sharing the eligible student will receive an email with their redemption code and instructions to activate the additional consecutive three-month Microsoft Office 365 University subscription.

Microsoft's offer commences at 12:00AM Pacific Standard Savings Time on March 11, 2013 and all Offer redemptions must be made via the Offer Site by 11:59PM Pacific Standard Time on May 12, 2013 or while supplies last at which time the Offer ends. Redemption codes must be used no later than May 12, 2014, Microsoft said.

The University plan includes Access, Excel, OneNote, Outlook, PowerPoint, Publisher and Word on Windows; and Excel, Outlook, PowerPoint and Word on OS X.