Libreoffice is a free open source office suit software that you can download and install for free. This is my favourite office suite and I even prefer it over the Open Office. Libreoffice has a set of writing and editing tools that resemble Microsoft Office.So if you already know how to open an office and write a document or spreedsheet then you will find Libreoffice way easier.
Libreoffice is free and there is no fear of copyright infringements. It works on almost all the major operating systems including Microsoft Windows, Mac OS X and GNU/Linux ( Debian, Ubuntu, Fedora, Mandriva, Suse,...)
Some features of Libreoffice
Here is a set of the main features that Libreoffice offers to its users :
It is free
It requires a download
It is available in several languages
It has LGPL public license
It is user friendly
It has an intuitive interface that you can easily customize
It is compatible with all major competitor file formats
It lets you import files from Microsot Word, Excel and PowerPoint and many other formats, and can easily save to Microsoft Office and other formats when needed.
Head over to Libreoffice and give it a try