Microsoft has updated the InfoPath 2003 Software Development Kit (SDK)

The Microsoft Office InfoPath 2003 Software Development Kit (SDK) is designed for solution providers (SPs), value-added resellers (VARs), and other developers who are interested in developing solutions with InfoPath 2003 and InfoPath 2003 Service Pack 1.

The InfoPath SDK includes documentation and samples that demonstrate development techniques for customizing and implementing InfoPath features, including integration with Microsoft Office Access 2003, Microsoft Office Word 2003, Microsoft Windows SharePoint Services, Microsoft BizTalk Server, Microsoft SQL Server, XML Web Services, Component Object Model (COM) components, and ActiveX Data Objects (ADO).

Microsoft Office InfoPath 2003 SDK contents:
Section 1: Getting Started
Section 2: Common Developer Tasks
Section 3: Best Practices
Section 4: Developer Sample Forms
Section 5: Tools
Section 6: Macros
Section 7: Code Libraries
Section 8: InfoPath Developer's Reference

Note For the most current version of the InfoPath SDK documentation, see MSDN Online.

InfoPath 2003 Software Development Kit (SDK)