StarCalc is a spread sheet, and can probably compete with Excel 5. StarOffice 3.1 comes with other programs too, which are ALL fully Internet integrated! So you can now easily share data between work mates and design your own web page using StarWriter.
Since the suite is modeled after Microsoft Office, people used to it can easily get to work with StarOffice 3.1, which is available in many languages, and offered for OS/2, Linux, PowerMac and Windows.
StarOffice 4.0 has also been recently release! Watch out for it!