LibreOffice

By downloading and installing a copy of LibreOffice, you get a simple-to-use yet powerful interface that is easy to personalize – Microsoft Office users will find the switch easy and painless, with a familiar look and feel.

LibreOffice is the power-packed free, libre and open source personal productivity suite for Windows, Macintosh and GNU/Linux, that gives you six feature-rich applications for all your document production and data processing needs: Writer, Calc, Impress, Draw, Math and Base. Support and documentation is free from our large, dedicated community of users, contributors and developers.

You can download, install and distribute LibreOffice freely, with no fear of copyright infringement.

From LibreOffice:

By downloading and installing a copy of LibreOffice, you get a simple-to-use yet powerful interface that is easy to personalize – Microsoft Office users will find the switch easy and painless, with a familiar look and feel.
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LibreOffice 3.6.5 is licensed as Freeware for the Windows operating system / platform without restrictions. LibreOffice is available to all software users as a free download (Freeware).

LibreOffice Virus and Malware Tests:

For security reasons, you should also check out the LibreOffice virus and malware test that has been uploaded; additional LibreOffice screenshots may be available, too.