PortICA is the name of the technology that "ports" the ICA protocol stack from Presentation Server / Terminal Server to a workstation OS. In other words, portICA lets you use the ICA protocol to connect to a Windows XP or Vista host acting as the server (for a VDI or blade PC scenario). Citrix is using PortICA instead of the built-in RDP-based remote desktop option in their upcoming XenDesktop product. (Note: All of the portICA technology described in this article is part of Citrix XenDesktop 2, currently in beta, scheduled for a May release.)
Why PortICA? A lot of VDI products are entering the market using server-based computing technology to connect to single instances of Windows XP or Vista instead of Terminal Server. Several companies, including VMware (VDM2), Quest / Provision Networks (Virtual Access Suite), and Ericom (PowerTerm) have real products on the market now.
Citrix also has a VDI product on the market called "Citrix Desktop Server," but this product is just a quick-and-dirty product that was thrown together fairly quickly only solves basic needs. Citrix's first "real" VDI product will be XenDesktop 2.
Anyone who's been in this industry more than a few days knows that connecting into a server-based computing environment via ICA is better than via RDP. And this is where PortICA comes in. It lets you use an ICA client to connect to a remote Windows XP or Vista instance via ICA, including support for all the add-on capabilities you'd expect like SpeedScreen, port mapping, and EMF-based printing. PortICA technology is one of the key features of XenDesktop 2.
Even though the purpose of this article is to discuss PortICA and not XenDesktop in general, it probably makes sense mention a few things about XenDesktop first though.
Microsoft, Cirtix, Windows XP, XenDesktop, ICA, PortICA, Virtualization, Knowledgebase