You must have a Macintosh running OSX 10.6 or higher AND Microsoft Office 2011

* Office 365/2016 for Mac is currently incomplete and not compatible, for more information and how to ensure compatibility, see our help for Office 365 Mac 

You may download and install your purchased software on two computers (a third is optional). You may use the software forever as long as your computer(s), operating system, and Microsoft Word support it.