FreeOffice

For years, there have been popular "clones" for Microsoft Office, including:
Apache OpenOffice http://www.openoffice.org/
http://www.openoffice.org/product/index.html

and
The Document Foundation's LibreOfficehttp://www.libreoffice.org/
http://www.libreoffice.org/discover/libreoffice/

Now, there's a new player in the office suite space, SoftMaker's FreeOffice:
http://www.techrepublic.com/article/finally-theres-an-open-source-drop-in-replacement-for-ms-office/
http://www.freeoffice.com/en/
http://www.freeoffice.com/en/discover/freeoffice-windows-linux