XenDesktop 5.5 includes the following new features and enhancements:

HDX MediaStream

• Second Generation Flash Redirection. Adobe Flash content can be redirected to the user device for local rendering in many more cases than before, resulting in even higher server scalability and a great user experience. Flash Redirection now supports WAN-connected users. Good results with video playback have been observed, even at high latency.

• Server-Rendered Video. For multimedia content that is rendered server-side, the need to configure complex policies for best performance under different network conditions has been eliminated. HDX MediaStream automatically adjusts to the effective network bandwidth to use the level of compression that delivers the best video experience (image quality and frame rate) while displaying non-video regions, such as text, at full clarity.

• Windows Media Redirection. A new end-to-end flow control and frame dropping capability has been introduced. This improves the user experience when the bandwidth available for viewing a Windows media video (WMV, MPEG, AVI, DivX, etc.) is less than what is required by the bit rate of the video, an issue increasingly experienced by customers as videos are recorded at higher resolution. This technology allows multimedia redirection to be used in more access scenarios, further reducing server CPU consumption. Priority is given to smooth audio playback and audio-video synchronization at the expense of the video, so video frames are dropped when the available bandwidth is too low. In Citrix's own comparison testing, this technology delivered a better-than-local user experience under the same bandwidth constraints.

• Multi-Stream ICA including UDP for Audio. XenDesktop 5.5 introduces the option of delivering ICA over multiple streams: four TCP/IP streams and one UDP/RTP stream (for audio). This gives full flexibility for QoS routing over the network and provides superior audio quality when there is packet loss or congestion.

• Citrix Receiver for Windows. Various enhancements in Citrix Receiver (formerly the Citrix online plug-in) offer benefits to users of softphones and unified communications clients:

UDP and RTP (Real-time Transport Protocol) support 

Improved multi-tasking with real-time applications

Smoother audio when network latency fluctuates ("jitter") 

Improved echo cancellation when using speakers and a microphone

HDX Broadcast

When running a typical office user workload, as represented by the standard Login Virtual Session Indexer (VSI) "Medium" knowledge worker test, Citrix expects customers to see a 30% reduction in bandwidth consumption along with reduced CPU consumption on the server (leading to higher server scalability) and improved desktop image quality on low bandwidth connections.

In addition, RDP protocol support in HDX Broadcast has been enhanced to support RDP 7.1 with RemoteFX.

HDX RichGraphics

• Microsoft RemoteFX Support. Microsoft RemoteFX, a feature of Windows Server 2008 R2 SP1 Hyper-V, uses server-side graphics hardware acceleration to deliver the full Windows 7 Aero and multimedia experience over a LAN-like connection. XenDesktop 5.5 supports RemoteFX using enhancements to RDP protocol support in HDX Broadcast and to Citrix Receiver for Windows. This is the first phase of a vision and collaboration announced by Citrix and Microsoft in March 2010.

• Windows 7 Aero Redirection. Aero Redirection leverages client-side graphics hardware acceleration to deliver the full Windows 7 Aero experience (including glass effects, Flip 3D, and Aero Peek) over a LAN-like connection. Using the DirectX 9 graphics processing capabilities of the user's rich client device (Windows XP/Vista/7 PC or higher-end thin client), Aero Redirection delivers an outstanding user experience that truly feels "like local", if not better. This is the first phase of a powerful new HDX technology based on DirectX graphics command remoting. Note: This feature is disabled by default. To use it, expand the HDX Policy node and click Users. In the ICA options select Desktop UI, and in the Settings area select Aero Redirection. If Aero Redirection has been enabled, click Edit; otherwise, click Add. From here, you can enable or disable Aero Redirection.

• 3D Pro Enhancements. In XenDesktop 5.5, HDX 3D Pro adds full multi-monitor support for Windows 7 desktops. This extends the best-in-class solution for remote access to professional 3D graphics applications and very large models to enable full desktop replacement. HDX 3D Pro also offers limited support for multi-monitor access to Windows XP desktops. Other enhancements include support for GPU-accelerated deep compression with NVIDIA Fermi GPUs and the addition of XenDesktop policies enabling administrator control of the end user image quality configuration tool. XenDesktop 5.5 supports the Multi-GPU Passthrough feature of XenServer 6.0, which is available on the Citrix Downloads Web site. HDX 3D Pro supports the Microsoft WDDM display driver model, enabling users to access their multi-monitor Windows 7 workstations from home or remote locations over a high speed Internet connection. The software intelligently collapses applications from the multiple monitors on the host machine to the available monitors on the remote device, and blanks the host monitors for data security.

HDX Plug-n-Play

New HDX Plug-n-Play capabilities include support for WAN-connected scanners (via the TWAIN standard) and Japanese and Korean keyboards. Usability of removable storage devices has been improved. Client Drive Mapping now supports read-only access on all Virtual Desktop Agents. Client Drive Mapping also supports Universal Naming Convention (UNC) path support on Virtual Desktop Agents with Windows 7 and Windows Vista environments.

Desktop Director version 2

A new version of Desktop Director is available for use with XenDesktop. For more information, see the Desktop Director documentation.