Citrix adds seamless app publishing from single-user desktop OSes! (Read the fine print though.)

In a MAJOR announcement from Citrix yesterday, the company finally plans to let customers connect to single seamless remote ICA applications running on single user (XP/Vista/7) hosts in the datacenter.

In a MAJOR announcement from Citrix yesterday, the company finally plans to let customers connect to single seamless remote ICA applications running on single user (XP/Vista/7) hosts in the datacenter.

Think of this just like published apps in seamless windows from a Terminal Server, except instead of a multi-user Terminal Server on the backend you have a single-user Windows desktop OS. This is useful in scenarios where you want to use server-based computing for seamless single app access, but your application doesn’t work on Terminal Server.

The feature is officially called “VM hosted apps” and it will be released in a few months as part of Feature Pack 2 for XenApp 5.

Use cases

Why would anyone want to use VM hosted apps? After all, it means that you’ll have to have a Windows desktop OS for every single app for every single user!

Clearly no one is suggesting that this replaces traditional VDI or Terminal Server published apps. Instead, it’s a great third option where you want server-based computing but you have a specific “problem scenarios” where you can’t use Terminal Server. Specific use cases for VM published apps include:

  • App compatibility problems, where the app just doesn’t work or isn’t supported on Terminal Server.
  • Compute-intensive apps, where you want to run an app on a single-user blade instead of a multi-user Terminal Server.
  • Graphically-intense apps, where you want a GPU on the host for each user. (Possibly even including Teradici’s PC-over-IP or Citrix Project Apollo?)
  • Apps with high availability requirements, where you want the ability to live migrate single instances from host to host.

Limitations of the initial Citrix release

This is a feature that people have been requesting for years, and just about everyone (myself included) are excited about it. So yay for Citrix!

That said, if you think the history of wanting it means that Citrix had plenty of time to put together an eloquent solution, you’d be wrong! It’s clear that the Feature Pack 2 VM hosted app capability is a reactionary “hack” that has the same feel as the Citrix Desktop Broker of 2006. For example:

  • Configuring VM hosted apps is done via yet another management console. (UPDATE: It's an MMC snap-in, so it can be plugged-in to the AMC)
  • VM hosted apps farms are not integrated with existing XenApp or XenDesktop farms. (So the VM hosted apps appear as their own farms which are aggregated via XenApp Web, etc.)
  • Configuring your VMs requires some very specific things. (Certain shortcuts in certain folders, etc.) It’s not as simple as publishing an app.
  • There is a 1-to-1 mapping between users and VMs. If a user needs two VM hosted apps, they need two VMs.
  • No pooled VM support. It’s one-to-one. (UPDATE: This is wrong, as per Vinny's comment below)

The fine print

There’s a strange twist to this announcement, namely, that this VM published apps feature is going to be a feature of XenApp, not XenDesktop. On one hand that makes sense, because this is an “app” feature, so it should be in the Xen“App” product. On the other hand, this is a feature that’s delivered from a “desktop” OS, and that’s normally handled by Citrix’s Xen“Desktop” product.

In some ways it doesn’t matter which product it’s in, because if you really embrace what Citrix is doing then you’re going to end up with both XenApp and XenDesktop in your environment. Then again, if they added this feature to the XenDesktop product, it might have led to a situation where people started publishing app their seamless apps via XenDesktop, which would be bad for Citrix since XenDesktop is about 1/3 the price of XenApp. (See my article from last year about the effective “app publishing tax” caused by this price difference.)

So pricing pressure plus the desire for product “purity” (apps from the App product, desktops from the Desktop product) led Citrix to make VM hosted apps a XenApp feature. Fine. But the other major problem with this is that since the VM hosted app feature requires one VM per user, there’s a LOT of back-end logistical management that needs to happen. When a user connects, it needs to make sure their VM is running, possibly power it up, grab one from the pool, reassign to the pool when they log off, etc. All of those needs, while complex, are already built-in to the XenDesktop product (since that product is designed to work with single-user VMs). Those features are NOT built-in to XenApp. But VM hosted apps are. D’oh! (Now it’s clear why there are so many limitations in this first release. I’ll bet if they would have added VM hosted apps to XenDesktop, it would have been seamless and slick right from the start.

The other weird thing about the whole “XenApp versus XenDesktop” capability is that you CAN publish full desktops from XenApp. So Citrix is already sort of breaking their product “purity” thing I mentioned earlier. But since this new VM hosted apps feature is a Xen“App” feature running on a desktop VM, Citrix had to specifically go out of their way to prevent users from publishing full desktops on single-user desktop VMs. They explicitly disable that capability, because if a XenApp customer could publish a single-user desktop, then they’d have no reason to also buy XenDesktop.

So the “what you can publish with which product” matrix is still a little arbitrary and weird, but whatever—I’m sure we’re still on the long slow march to Citrix combining both products in a way that hopefully doesn’t increase the price for everyone.

Oh, and speaking of fine print, keep in mind that this VM published app feature WILL require a Microsoft VECD license on top of the TS CAL license you already have for each XenApp user.

How other vendors handle VM published apps

Of course Citrix is not the first vendor to offer published applications from single user desktop VMs. Quest’s vWorkspace product has been doing this for years. And just in the past few days, I heard (from Benny Tritsch at BriForum and from Peter Ghostine on my webcast with him yesterday) that Microsoft was planning this feature for Windows 7.

And then there’s VMware, which still doesn’t even offer single app publishing. Their VDI solutions are all-or-nothing. (Either you have a full remote desktop, or you don’t.) And if you want to combine local and remote, you have to deal with two whole desktops. Sure, VMware can use ThinApp to drop apps into the remote VDI desktops, and they can use ThinApp to drop apps onto local client desktops. But they have no way to connect a user via a remote display protocol to a single app.

Bottom Line

Love the feature. Glad it’s finally here. Too bad it’s half-baked. Better late than never.

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Interesting. I guess I just assumed they would do it the easy way and "throw a switch" in XenDesktop. Bummer...


Thanks for the insight Brian... as always! :-) Just a couple of corrections which I will also update on my blog post.

Pooled VM's - Actually, this is supported and is the most recommended way of implementing this feature once it is available.

IMA - In trying to help folks understand that they are separate farms, I went a bit too far and said it doesn't leverage IMA. It does... just as a separate farm.

Consoles - The consoles are separate but they do come together via the MMC to create that one stop shop. Plus, WI is going to have a new MMC snap-in as well which is awesome. We'll have to get you some screen shots of that.


you should be able to publish a script or a custom launcher to get multiple apps from a single "vm-hosted-app". It's no as nioe as publishing multiple apps but it should do the trick.


Thanks for the clarifications Vinny! I've made the edits to the article.


Ilan is correct. You can also have multiple apps in the VM and put a batch or script in the application folder to make multiple apps open on launch. Also, if you have helper apps installed into the VM and they are needed by the primary app, they will be opened automatically based on file type association. You should also be able to have apps streamed or opened from a server session via file type association too.

That said, I'm with you guys. It could be easier to support multiple apps in one VM so I want to see that soon too.


Firstly I think this a good thing, and it makes sense to help out the majority of people who use XenApp that have the odd weird app that causes problems. So yes making XA better for that use case is cool.Now I can finally tell those a-holes at Bloomberg that I am going to remote their stupid app without buying their $$$$$$$$$$$$$$ web crap. They are the worst license thieves in the Market data industry. Now people can finally share BB terminals at the same price and they can't do jack about it. HAHAHAHAHAHAHAHA.......

Secondly, MS should make VECD user based to enable service providers. Again monopoly thinking. Without it DAAS will not take off, and I believe that is exactly their intention. Hello EU anybody home, want to have some fun?

Brian XD is slick? Are you kidding has a long way to go before that. I do however agree and have said it numerous times, ONE product. Also it makes sense to have the products behave like each other from an architecture point of view so we can really get the benefit out of our $$$$$$ licenses. They better not increase price if they bring them together, it makes no sense.

Quest. Yes, but they only offer RDP which SUCKS many times over even RDP 7 is more hype than anything for non LAN based senarios. In addition Quest has a TINY <footprint> and there so called price discount is washed away in large deal by Citrix so there is no way I am going o complicate things by using Quest to fix Bloomberg!!!!!


Brain is right to point out that you need VECD license as well.

Just keep in mind with this new delivery method, it is just like streaming an app from a licensing point of view.

You must still comply with the licensing model of the app. If the app is licensed by Device (like all Microsoft Apps Office Project Visio etc) then you must lock down the access by Device.

My view is the numbers of clients deploying via this method will be small but a new method of deploying apps that will help some clients has to be a good thing.Good work Citrix for making it an option.


Yes finally. Im lovin' it!


Sounds like a step in the right direction,  but what I really still want to see if the option to ICA to a Vista/XP desktop (not VDI).


@DaveH - You can do this now.  It's called XenDesktop.  It doesn't need to be VMs (which is what I assume you mean by VDI).  You can install the XenDesktop Agent on physical PCs and broker an ICA connection directly to a full desktop using the ICA protocol.  If you're not talking about a full desktop and are just talking about an individual seamless published app from a desktop OS, then that's what this article is about.



Did you mean 'eloquent solution' or 'elegant solution'?