Apple says iWork is compatible with Microsoft Office. But what does that really mean and is it true?
It's true that you can move documents between iWork and Office. But when you do, they may look or function differently than they did in their parent programs. In Macworlds recent feature comparing Word and Pages, Excel and Numbers, and PowerPoint and Keynote , we discussed the differences in features between those programs. But (as several readers pointed out in comments to those stories), we didn't cover the file-compatibility or interoperability issues that arise when you're trying to move documents from one suite to another.
Office Files in iWork: When you attempt to open an Office file in iWork using File: Open, iWork doesn't really open them: it imports them instead, creating a new translated file in Pages, Numbers, or Keynote format and leaving the original Word, Excel, or PowerPoint file untouched.
iWork applications can import files in Microsoft's newer Open XML file formats (which use the filename extensions .docx, .xlsx, and .pptx). These are the default file formats of Office 2008 for Mac, and Office 2007 for Windows. Office 2004 can only create the older Microsoft formats (.doc, .xls, and .ppt), but iWork can import these as well.
If you have both Office and iWork installed on your Mac, and you want Pages to open when you double-click a Word file, select the file and chose Get Info from the File menu. Expand the "Open with" section and chose Pages from the popup menu.