Retains the essential look and feel of Microsoft Office 2003 and earlier versions, instead of imitating the new ribbon interface of Office 2007. Anyone familiar with Microsoft 2003 or below should be able to jump straight into OpenOffice with minimal, if any, training.
If you've been thinking about taking the plunge into Microsoft Office 2007 (or 2008 on the Mac), which often requires training because of significant interface changes, you should be evaluating OpenOffice as well.
One attractive feature of OpenOffice is that it's the only major application suite that runs on Windows, Mac OS X, and Linux with almost exactly the same feature set on all platforms.
For anyone thinking of switching from Office to OpenOffice, the biggest question is, How well will OpenOffice handle your old Office documents and worksheets? The answer is, incredibly well, even with the new Office 2007 formats.
In addition to read and write support for the Microsoft Office binary file formats (.doc, .xls, .ppt, etc.), OpenOffice is capable of opening files created with Microsoft Office 2007 or Microsoft Office 2008 for Mac OS X (.docx, .xlsx, .pptx, etc). Thus, OpenOffice users can interact with users still using Microsoft Office.