View Office Documents Online

Microsoft provides a free (I love free) tool that displays Word, Excel or PowerPoint files inside your web browser.  If you're a web developer, you can provide a link as an alternative to your customer downloading a document.  

But being a Mac user who refuses to shell out two Benjamins for Office at home, I can view documents with the full fidelity only Microsoft manages, and then download them as PDFs if necessary.  The formatting and layout in Word documents is maintained, Excel workbooks can be filtered and sorted, and animations play in PowerPoints.

http://products.office.com/en-us/office-online/view-office-documents-online