The OpenOffice Project has released OpenOffice 2.3, an open source office suite for Linux, Solaris, and Windows that saves all its files as zipped XML. There's also an alpha-quality version for the Mac (X-Windows no longer required). Version 2.3 adds a new report designer, provides localizations for several more languages including Tagalog and Frisian, improves charts and databases, and fixes numerous bugs.
I tried out the Mac version. OpenOffice is improving but even leaving aside stability issues that probably don't exist on other platforms, it's clearly not ready to replace Microsoft Office anytime soon. It's still missing some really basic functionality like a scrolling view of a word processing document. There are also numerous UI inconsistencies that need to be cleaned up. Can you spot this one? (There's one problem on all platforms and an extra problem just on the Mac.)
Actually looking at that dialog again, I see three problems, two for all platforms and one only on the Mac. Yes, I'm being picky, but it's getting the little stuff like this right that really makes an application feel and look professional and clean. Outside of the Mac world, most open source developers aren't nearly picky enough. (Firefox and recent version of NetBeans are two notable exceptions. It's no coincidence that both of those projects include significant proportions of PowerBook-wielding developers.)
I tried to report some of these problems, but their bug reporter requires registration, and never sent me a password. :-( OpenOffice is dual licensed under the LGPL and Sun Industry Standards Source License.