LibreOffice is Free and Open Source Software.
This leading Microsoft Office alternative has performance improvements particularly around Writer (its word processor) and Calc (spreadsheet) components, the tabbed compact user-interface work is now available throughout more of the suite, better PDF export support, continually ongoing improvements to the Microsoft Office file format interoperability support, and a plethora of other improvements.
https://www.libreoffice.org/download/download/?type=win-x86&version=6.3.0&lang=en-US
