A customer relationship management (CRM) system utilizes a form definition, user interface (UI) definitions, and UI code to generate Web pages for interacting with CRM data. A CRM plug-in is configured to execute in conjunction with a personal information manager (PIM) client application and to utilize the same form definition, UI definitions, and UI code utilized by the CRM system to generate the Web-based CRM interface. The UI definitions are utilized to present UI controls for performing CRM-related functionality in the context of a UI generated by the PIM client application. The UI code utilized by the CRM system to implement Web-based UI controls can be utilized to implement the UI controls in the context of the PIM client application. The form definition utilized by the CRM system might be utilized to display CRM fields in the UI presented by the PIM client application.