Not too long ago, I posted an article introducing the availability of ClearType on Citrix XenApp.

Helge Klein - one of my favorite bloggers, has taken it to the next level, he wrote a technical article explaining in great details how to configure ClearType on both XenApp 4.5 and XenApp 5.0, along with their respective requirements. Here's a snippet of his post.

With the release of the hotfixes KB946633 and PSE450R02W2K3037 ClearType font smoothing is finally available on both the current and the upcoming Citrix flagship products Presentation Server 4.5 and XenApp 5.0. Remains the question of how to configure it.

Windows has a GUI for configuring font smoothing (well hidden in the display properties). XenApp does not.

Each user of a published desktop can use the Windows GUI for configuring font smoothing. But what about the majority of XenApp users who only use published applications and do not have access to a published desktop? I do not know. Of course, the admin could set the font smoothing type in the registry for them. But even then users have no means of changing their setting.

Enter XenApp 5.0 and ICA client 11. If and when those two are at the server respectively client end of an ICA connection, the whole thing works the other way round: The ICA client reads the font smoothing type of the Windows client and transmits it to the server who then activates the client's setting for the current session. This even works across reconnects: During a reconnect from a different machine the new client's setting is read and transmitted. If it is different from the previous client's setting the font smoothing type of the session is changed on the fly.

This approach clearly has its advantages: No problems with published applications. Additionally, remote applications always have the same look as local programs.

But wait: What if the client is not a Windows client? Then we are back to the pre-XenApp days: Configuration on the server.

Configuration Overview

Just in case you got confused: The following table lists all requirements and configuration options:

Continue reading Helge's blog post here.

ClearType (aka Font Smoothing) is a software technology developed by Microsoft that improves the readability of text on existing LCDs, such as laptop screens, Pocket PC screens and flat panel monitors. With ClearType font technology, the words on your computer screen look almost as sharp and clear as those printed on a piece of paper.

For the longest time Microsoft ClearType has been working properly inside an ICA session with Citrix Presentation Server running on Windows 2000 Server, but it did not work with XenApp 4.5 running on Windows Server 2003.

As previously mentioned Citrix was working on an update to XenApp 4.5 for Windows Server 2003 to utilize this new Microsoft Update for Terminal Services to provide ICA users with ClearType support.

Well, on July 7th (yesterday) Citrix released a hotfix for XenApp 4.5 on Windows Server 2003 that enables ClearType on its XenApp 4.5 Servers.

Note: This patch also rectifies several other issues in XenApp 4.5. You can find the list of fixes by clicking here.

If you want to learn more about ClearType, I can suggest two great articles on this subject:

• Jeff Muir on ClearType and Terminal Services.
• Helge Klein has written an excellent article on ClearType Bandwidth requirements on Terminal Services.

Cheers,
Gus