In this chapter, we learned about the Microsoft Dynamics CRM 2015 SDK feature. We discussed various tools that come with the CRM SDK. We learned about the different CRM APIs and their uses. We learned about different programming models in CRM to work with the CRM SDK, using different methods in CRM web services. We also discussed new enhancements for developers in CRM 2015 update 1. In this chapter we created a console application using a client API. Finally, we discussed various options for integrating CRM with other ERPs and custom web sites. In the next chapter, we will learn about creating plug-ins and custom workflows.