For the most part, Microsoft Dynamics CRM 4.0 is backward compatible with Microsoft Dynamics CRM 3.0. This section contains the information that you need to upgrade your code to the 4.0 version.

Developers who want to take advantage of new Microsoft Dynamics CRM on-premise features, such as multi-tenancy and Microsoft Dynamics CRM Online, can reuse most of their current investment in application code. Existing application code can be easily extended to use the new or improved Microsoft Dynamics CRM Web services, requiring only a recompile and redeployment.

In This Section

Upgrade Issues for Workflow and Callouts

Describes the support provided for Microsoft Dynamics CRM 3.0 callouts and workflow .NET assemblies.

Using the 2006 Endpoint

Contains information about how to use the 2006 (Version 3.0) Web services with Microsoft Dynamics CRM 4.0.

Upgrading Your Existing Code

Contains a sample from Microsoft Dynamics CRM 3.0 showing the changes you need to make for this version.

Deprecated Classes

Lists the classes deprecated in this version.

Deprecated Entities

Lists the entities deprecated in this version.

Deprecated Messages

Lists the messages deprecated in this version.

Related Sections

Developing Custom Solutions

Describes how to write code to create custom solutions using Microsoft Dynamics CRM 4.0.