Application delivery is about receiving applications from anywhere on any device that can be anywhere. Application delivery is Citrix's sweet spot as they have been in this business since the start of the company in 1989. It started out as MetaFrame for Windows, evolved as Citrix Presentation Server, migrated to XenApp, and has now morphed into XenDesktop for the virtual delivery of both applications and desktops. With the popularization of virtualization for data center devices, such as network, compute, and storage, the virtualization of applications and now desktops is becoming more popular. Also, the options for the delivery of apps and desktops are abundant and powerful when using the complete vision of application delivery networks formulated with Citrix products. In this chapter, you learned about application delivery and how additional Citrix products complete the end-to-end desktop and application delivery vision. In the next chapter, we will discuss the XenDesktop SDK.