Patches and updates
ESRI Software 9.1 Library - Developing with ArcObjects
This book discusses the customization possibilities available to the ArcGIS Desktop user and developer. These include adding commands to existing toolbars and creating your own tool to perform a custom GIS operation. This book also provides an overview of the ArcGIS architecture, introduces you to the supported application programming interfaces (APIs), and includes a number of scenarios that step you through the typical development process.