[This is preliminary documentation and subject to change.]
Any application that uses Active Accessibility to gain information about objects is considered a client. Typically, clients are accessibility aids, such as screen readers, screen enlargement utilities for low-vision users, and speech recognition utilities. However, Active Accessibility provides technology useful to many types of applications. For example, testing tools can use Active Accessibility to query the state of applications and objects. Development tools, such as object browsers, might need the run-time information that Active Accessibility provides.
To implement an Active Accessibility client, you must know how to call an accessible object's IDispatch or IAccessible interface methods. For more information on IDispatch, see IDispatch Interface.