rdesktop is an open source client for Windows NT Terminal Server and Windows 2000/2003 Terminal Services, capable of natively speaking Remote Desktop Protocol (RDP) in order to present the user's NT desktop. Unlike Citrix ICA, no server extensions are required.

rdesktop currently runs on most UNIX based platforms with the X Window System, and other ports should be fairly straightforward.

rdesktop project was initially written by Matthew Chapman based on various scarce documentation, wire sniffs, and trial-and-error.