Here are the steps you need to follow to develop an ILC application:

1. Decide which languages to use.

   Your application code will need to follow the rules in the compiler programming guides and the z/OS Language Environment Programming Guide. Use the pairwise language chapters to identify what levels of HLLs you should be using.

2. Make sure all your ILC applications are Language Environment-conforming.

   Each chapter gives the basics of what you need to do to get your ILC applications to be Language Environment-conforming (adhering to Language Environment's common interface). For detailed information about migration, see the language migration guides.

3. Decide which language will have the main routine.

   Language Environment allows only one routine to be the main routine in an enclave. Each chapter describes how to determine the main routine in an ILC application. If you are using a multiple language application, see Communicating between multiple HLLs to determine how to designate a main routine.

4. Learn how to declare and use data across HLLs.

   Each chapter describes how to use data in an ILC application.

5. Learn how to mix HLL and Language Environment operations. Each HLL has a unique way of using storage, return codes, and performing condition handling. Each chapter describes how to mix these HLL-specific constructs.