Perhaps you have already tried the latest Microsoft Office 2013, but don't plan to upgrade your operating system or hardware to meet its requirements; or you simply don't want to use the Cloud feature, then you will find Kingsoft Writer a good replacement for Microsoft Word. Kingsoft Writer just run locally and can handle documents created with Microsoft Word 97-2010, while occupying much smaller space than Microsoft Word.
The interface of Kingsoft Writer Free is much like that of Microsoft Office 2003/2007. If you are familiar with that, you can save the time to adapt to a new interface. Both classic style and 2013 style interfaces are available.
With a small size, Writer runs much faster, and allows processing of multiple documents in different tabs.
It is compatible with Microsoft Office 2007 file formats (*.docx), allow one to edit and save documents as DOCX. In addition, it introduces the paragraph layout tool, which is a smart and useful feature not available in Microsoft Word.
Overall, it is a great replacement for Microsoft Word, not only for its price - free, but also for its good compatibility and friendly interface.