Remote Desktop on Linux?

With the momentum behind desktop virtualization; both with VDI and Remote Desktop Sessions (formerly Terminal Services), more and more people are looking for ways to access the Windows Desktop from platform other than Windows. Citrix offers the Citrix Receiver which supports virtually all platforms, but if you want to use the Remote Desktop Protocol (RDP) your choices are limited. This is a list of the RDP clients I have found for Linux:

Unfortunately none of these support more than RDP v5.1, which do not offer any of the newest features such as multi monitor support etc.