LibreOffice
LibreOffice is a free and open-source office productivity software suite. The LibreOffice suite consists of programs for word processing, creating and editing of spreadsheets, slideshows, diagrams and drawings, working with databases, and composing mathematical formulae. LibreOffice uses the OpenDocument standard as its native file format, but supports formats of most other major office suites, including Microsoft Office, through a variety of import and export filters.