Microsoft has released a Service Pack for Office 2001, the Mac version of the megalithic productivity suite. A Service Pack is what Microsoft typically calls their patches and updates. Service Pack 1, as this is dubbed, is designed to smash some bugs and improve OS 9.1 and Classic support in OS X. According to Microsoft.
The Office 2001 Service Release 1 is a collection of product updates for all of the applications found in Office 2001. It provides Office 2001 customers with the latest fixes for issues in existing product features, while offering continued compatibility and support for users of Mac OS 9.1 and Mac OS X (classic environment). Service Release 1 is not a required upgrade, but Microsoft recommends it for Office 2001 users.
You can download the Service Pack at Micrsoftis Web site, where you can also find more information. C|Netis Joe Wilcox has an excellent report discussing Office, Outlook Express, and Internet Explorer for Mac OS X, including some comments from Microsoft Mac Business Unit people.