When you develop an application, you must make sure that the instance of the ChorusOS operating system that the application will run on contains the optional components your application requires. For example, if your application uses semaphores, you must include the SEM option. See "Optional Operating System Services" for information about optional components of the ChorusOS operating system. See Chapter 3, Configuring and Tuning for information about configuring the ChorusOS operating system to include the components you require.