AbiWord Version 2.6.5 Works With Word 2007 and OpenOffice Writer
AbiWord has been my favorite open source word processor for a long time, and it's now out in a new version 2.6.5, which adds some excellent features. If you haven't used this application (for Windows or Linux) before, definitely download it, and if you already use it, go for the upgrade. AbiWord has always had excellent support for many file formats, but one of the best things about the new version is that it supports Office Open XML filters, and that means you can open and edit both Microsoft Word 2007 and OpenOffice Writer files with it. Here's more on what's under the hood.
The full list of improvements and bug fixes in the new version of AbiWord is found here. There are many improvements to the LaTex export filter, including support for exporting equations.
Without a doubt, though, most current users of AbiWord are going to want to upgrade for the Office Open XML filters, for faithfully importing tables, formats and much more from Word 2007 and OpenOffice Writer documents. (AbiWord's interface is very similar to Word's.) The features supported are: formatted text, formatted paragraphs, page breaks, columns, tab stops, footnotes, endnotes, headers/footers, fields, images, hyperlinks, bookmarks, lists, tables, and text boxes.
If you're new to AbiWord, you can take a tour of the application's Advanced Document Lyout features and more here. There are also many screenshots available online showing AbiWord running on various platforms, although the shots do not show the brand new version.