These free office OS software supports all document formats including those of Microsoft and finally give MS Office a break.
Apache OpenOffice: The free, open productivity suite
Apache OpenOffice is named amongst the well known open source office suites available today. It if packed with tools for word processing, spreadsheets, presentations, graphics and databases. Apache OpenOffice can save your documents in OpenDocument format, read-only Microsoft Word documents of proper Microsoft Word format.
It is released under the Apache License. The recent 3.4.1 version of Apache OpenOffice is supported by Microsoft Windows, GNU/Linux and Mac OS X operating systems. And do not carry any licence fee.
The suite includes: Writer - the word processor, Calc - the spreadsheets app, Impress - the alternative power point, Draw - the substitute of paint brush, Base - a database tool for creating and managing tables, forms, queries and reports, Math - it creates mathematical equations via graphic user interface or by manually typing formulas in equation editor.
LibreOffice: A powerful open source productivity suite
The Document Foundation's LibreOffice suite is a division of OpenOffice, as the underlying coding is the same. LibreOffice features the same six applications that Apache have; OpenOffice-Writer, Calc, Impress, Draw, Base and Math. The only difference between the two suites are the applications features, usability and community support. LibreOffice believed to be more actively developing suite than OpenOffice.
It is licensed under the GNU Lesser General Public License (LGPL) 3.0. The latest version v3.5.6 of LibreOffice supports Windows, Macintosh and GNU/Linux systems.
NeoOffice: Office applications for Mac OS X
The NeoOffice suite is an OpenOffice division too but is meant for Mac OS. It has almost all of the features available in OpenOffice.org but is focused on Mac users, it integrates the OS X interface with use of Mac OS X fonts and printing services.
The newest version 3.3 of NeoOffice, supports high resolution text drawing on Retina displays, is compatible with Mac OS X 10.8 Mountain Lion and Gatekeeper, and native Mac OS X text highlighting. It also lets Mobile users securely share NeoOffice data with other computers and devices. It is licenced under the GNU General Public License.
Google Docs: Create, share and collaborate online
Google Docs is an office suite that works on online module. It lets users with Google account create, share and collaborate on the internet. It offers to its users tools for documents, spreadsheets, presentations, drawings and forms, which are stored on Google's cloud service Google Drive.
It is integrated to other Google services like Gmail, GChat, Google+, Google Calendar and Google Drive. And being based on cloud you can use your files anywhere from any device. Though Google Docs is not open source, but it is free and works perfectly as the office suite.
KOffice: The integrated office suite
KOffice is equipped with the three major tools of office suites namely word processor, spreadsheet and presentation application. Koffice's latest version is 2.3.3 and is licensed under the LGPL 2.0. It is compatible with Windows, Linux, FreeBSD and Mac OS X systems.
