- vSphere is the name of VMware's virtualization products/suite.
- ESXi is the name of the operating system, installed on server hardware on which the virtual machines are running.
- VMware View is a software solution to provide virtual desktops, like Citrix XenDesktop.
VMware does not offer a product like XenApp. However, more and more companies are going to run Client-Virtualization (VMware View, XenDesktop) instead of XenApp. With VMware View you can provide applications directly installed on the virtual desktops as well as provided on demand using ThinApp.
André