Added information about specifying action input and output, and about bringing Tiger actions forward to Leopard.

In the section Action Input and Output, updated information about actions that don’t require input and don’t supply output.

In the section Property Keys and Values, in the description for the key AMCategory, removed the incorrect statement that Automator generates a log warning for actions brought forward to Leopard (OS X version 10.5) from Tiger (v 10.4).

For HTML version, added TOC links to additional class and constant reference documents. For all versions, added document links to See Also section in Introduction to Automator Programming Guide.

Added several debugging tips.

See Frequently Asked Questions About Debugging Automator Actions.

Documented the revised category values for AMCategory in Property Keys and Values.

Clarified the usage for AMIconName in Property Keys and Values, including new behavior supported in OS X version 10.5.

Clarified usage of AMWarning, AMAccepts, and amlint, and corrected a typo in listing "Reporting a fatal error to Automator."

The section Debugging and Testing Shell Script Actions now describes where to view error information on an error exit from a shell action.

Added information on actions as Universal Binaries to "Automator and the Developer."

Various bug fixes.

Added "Defining Your Own Data Types" and fixed several bugs.

Added section on programming implications of loadable bundles; fixed bugs.

Updated with information about new development features introduced in Xcode 2.1, including the shell script action.

New document that explains how to create actions--loadable bundles that perform discrete tasks--for the Automator application.