Microsoft may release Office for Linux. Who is gonna buy? Why must pay for a software like Office where you have best alternatives out there. LibreOffice 4 is the most stable release version where include important changes and improvements. Is full compatible with Office documents and is free.
LibreOffice is a open source personal productivity suite for Windows, Macintosh and GNU/Linux, that gives you six feature-rich applications for all your document production and data processing needs: Writer, Calc, Impress, Draw, Math and Base.