Windows Server 2003 is dominant today in Citrix XenApp environments. In fact we are currently at the peak (or nearly so) for a W2k3 installed base for Windows servers in general. As our customers look forward they will be faced with some potentially thorny issues when moving to Windows Server 2008. The main question is whether to go to the first W2k8 release (I will call it "R1" for the sake of simplicity) which includes both 32-bit and 64-bit versions or to skip R1 entirely and go with the recently released R2 which only supports 64-bit.

Based on several discussions we have had with partners and customers there seems to be a continuum of opinions. On the one extreme we hear folks saying that they will stick with 32-bit until it is ripped away from their cold, dead hands. These are among the more conservative who fear the expense and churn of having to validate all of their thousands of 32-bit applications on a 64-bit environment. They have told us they will stay on W2k3 until extended support is complete and then probably go to R1 and milk that for all it's worth to avoid the inevitable. That would mean sticking with a 32-bit OS until possibly 2018 (should we all be retired by then?) going by the Microsoft Lifecycle table for Windows Server 2008! On the other extreme are a few bleeding edge types who have decided to skip R1 and go directly to R2 and bite the 64-bit bullet at the same time as they migrate their environment from W2k3 to the newer OS. In between are those who will move cautiously if begrudgingly over time to the new OS version to avoid falling into the extended maintenance window.

One of the main concerns is, of course, that R2 is 64-bit only. While Microsoft has been stating for some time that Windows on Windows 64 (WoW64) will solve the problems associated with running 32-bit apps on x64 platforms, many customers are still worried about 32-bit apps with 16-bit installers and the ever-present 32-bit drivers. Not to mention, 16-bit apps. None of these will not work on WoW64 environments. On the other hand, don't customers have to test all their apps when transitioning from one OS platform (W2k3) to another (R1 or R2) anyway? What extra work is involved when validating apps on x64 versus just transitioning from one version of the OS to another? Of course out lives would be easier if everyone hopped to the new OS version ASAP so we did not have multiple platforms to support but the reality is quite different. We need to know what your thoughts and plans are on this one.

So this brings me to my questions for the community:

• What do you have to say as customers and partners?
• Will you stick to 32-bit as long as humanly possible?
• Do you have older apps with 16-bit installers or 16-bit apps? What is the plan there? Re-write or retire?
• What will you do about 32-bit drivers? Printer drivers? Will XenApp's Universal Print Driver solution be the answer?
• What has been the experience for those who have made the switch to 64-bit?

Give us your comments and take the poll below.

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HDX MediaStream does a fantastic job of reducing the network bandwidth requirements for streamed video compared with rending the video on the server. When using HDX MediaStream your bandwidth requirements roughly equal the bit rate of the source video file. For lower quality clips, like those found on YouTube, this is around 256Kbps. For full HD content the bandwidth requirements can be as high as 8Mbps.

While this works great over a high speed LAN, trying to push that amount of data over typical branch office T-1 is another story. This problem is magnified even more when you have multiple users in the branch office who are repeatedly pulling down the same video content. In this situation, the video quality suffers and other business applications can be impacted. This issue has nothing to do with XenApp or XenDesktop. It is purely a function of the size of video file and the limited amount of available network bandwidth.

What can you do about this? Well if the culprit is the latest viral video making its way around the Internet you could attempt to block access to sites like YouTube. However, what if the video is for legitimate business purposes? I talked to one customer at Synergy who is rolling out a corporate compliance training video to their entire company using XenApp but is worried about the impact to network bandwidth.

Enter Citrix Branch Repeater and HDX IntelliCache. With Branch Repeater 5 we now participate in the ICA session and accelerate the ICA virtual channel used by HDX MediaStream. The first time the video is streamed to the branch office, Branch Repeater caches the content locally. The next time the video is requested, Branch Repeater serves the content from its local cache rather than pulling it across the WAN. Using branch caching, you can reduce the bandwidth requirements for on-demand videos by up to 90%.

Don't just take my word for it. You can see a demo if this in action on the latest edition of Brian Madden TV. (If you don't want to watch the entire episode you can jump ahead to 5:49 into the clip).

HP just announced their next generation G6 ProLiant and BladeSystem servers powered by Intel Xeon 5500 (Nehalem) processors. My engineering friends suggested that the new Hyper Threading Technology in the 5500 processors is worth reading up on ... see the link in Pat Gelsinger's blog post for more on this front. Previously we talked about HP testing, and new performance characterization work just completed by HP indicates that a 2P HP BL460c G6 server equipped with the Intel Xeon X5570 can provide optimal support for up to 402 users when running HP's most aggressive test workload in a 64-bit HP Server Based Computing environment. The HP test results demonstrated that Hyper-Threading Technology was able to enhance performance by 41%, and that Nehalem provides a 2x performance improvement over the previous platform. Get all the details for yourself in the HP paper here. This BL460c G6 paper is the latest in HP's extensive library of performance characterization papers covering XenApp and XenServer with HP servers.

The HP G6 product release includes six new HP ProLiant servers certified with the new free Citrix XenServer. XenServer is certified on the: HP ProLiant BL490c G6, BL460c G6, DL380 G6, DL360 G6, ML370 G6, and the ML350 G6 models. This takes the total number of XenServer certified ProLiant models to 27!

Yup - HP now offers no less than 27 server platforms certified with XenServer!

You might have already seen the announcement of Citrix Presentation Server 4.5 Feature Pack 1 and its big features (SmartAuditor, EasyCall, Simplified licensing etc). This article is to talk about improvements that have not been highlighted in our marketing message but do have high value for some customers and partners.

1. SecureICA (128-bit encryption) for x64 platform
Our previous PS 64-bit release did not support this and we have now added support for this feature.

2. Client certificate support
The ICA Client now supports client side certificates. For e.g. if you configure Access Gateway to require SSL certificates then the client can present one during the SSL handshake. Jay has the details in his blog

3. Multi monitor enhancements

Several enhancements and fixes have been made e.g. dialog boxes and GINA windows don appear between the monitors, a primary monitor can be selected for application launch, a hot key is available to minimize a published desktop (useful when in full screen mode), supports shaped monitors by auto detecting the monitor configuration, a desktop session can be resized so it can occupy the entire real estate etc.

4. Presentation Server SDK now includes SmartAccess extensions

Presentation Server SDK has been updated to allow enumeration of SmartAccess filter information for active sessions on Presentation Server. These filters are provided by Access Gateway as a result of policy evaluations which may include endpoint analysis results. This is great way for partners to extend our SmartAccess functionality.

5. Icon support for WI PN Agent

WI and PN Agent now support true application icons (including 16x16, 32x32 and 48x48 size icons) and hence icons will now look original (as opposed to being stretched or shrunk). We do cache these icons on the client and hence you will not see any increase in network traffic (except for a very small increase the first time a user launches the new client from a new device)

6. Large application profiling support for application streaming

Microsoft CAB file has the limitation that each CAB cannot be more than 2 GB in size, and cannot have more than 64,000 number of files in it. This puts limits on large application profiling. We have now worked around this limitation so that extremely large applications can be profiled through application streaming profiler.

7. Web Interface client detection wizard for enhanced end user usability

WI now does a much better job in bootstrapping a user when they are coming from a new device to access applications. This feature can be very useful when users are coming from locked down machines/browsers with high security settings as it can properly guide a user to getting to their application fast.

8. Support for DirectX/WPF applications

PS 4.5 Feature Pack 1 now supports WPF (Windows Presentation Foundation) applications. Though there are currently not many WPF applications, many application vendors are embracing this platform for their next generation application development. This is our first step in supporting WPF applications (using server side software rendering) and please check out Derek's blog on what we are doing for the future

9. Windows Mobile 5 and ActiveSync support

This release now adds support for Windows Mobile 5 based smart phones and PDAs to sync data (application data, files, e-mail etc) with ActiveSync 4.x as a published application.

10. Updated PS Unix

Citrix Presentation Server for UNIX 4.0 now supports Solaris x86/x64 platform. This is in addition to our current support for Solaris SPARC, IBM AIX and HP-UX platforms. This new Solaris x86/x64 release contains several enhancements since the initial release of PS for UNIX 4.0 and is available to all customers current on Subscription Advantage. You can log into mycitrix and get the bits from the download section.

Both IBM and HP ship and fully support Solaris on their x86/x64 server lines so customer options are not restricted to Sun Microsystems own x86/x64 servers when delivering solutions with Citrix Presentation Server for UNIX 4.0. Sun Microsystems also provides Solaris only support options for delivering solutions on x86/x64 servers from other manufacturers.

The PS UNIX platform support page has the details.

Additionally, Presentation Server 4.5 Feature Pack 1 contains an updated PS 4.0 UNIX release (all platforms) with the latest updates and ability to consume Platinum licenses.