From LXF Wiki

AbiWord is a word processor built around GTK 2 (and optionally Gnome), featuring MS Word file import facilities. Its main competitors in the open source arena are KDE's KOffice and OpenOffice.org, but unlike the former it doesn't require a whole desktop environment to run, and unlike the latter it performs well on older hardware.

Most Linux distributions include AbiWord, but you can also download it from http://www.abisource.com

AbiWord is also available for Windows.