Citrix Project Alice: Reverse Seamless Windows

One of the cool research products I saw when I visited Citrix's advanced products group in Sydney a few weeks ago was something called "Project Alice," or "Reverse Seamless Windows." Everyone is familiar with the concept of seamless windows, where only a remote application's window is visible on the client instead of the entire remote desktop.

One of the cool research products I saw when I visited Citrix's advanced products group in Sydney a few weeks ago was something called "Project Alice," or "Reverse Seamless Windows."

Everyone is familiar with the concept of seamless windows, where only a remote application's window is visible on the client instead of the entire remote desktop. "Reverse seamless" is the flip-side of that concept. It's when a client device uses a full-screen remote windows desktop, but then individual LOCAL applications running on the client "poke through" the remote window to appear as individual applications within the remote desktop session.

The technology behind reverse seamless windows is fairly straightforward. In fact some folks from Login Consultants demonstrated this via something called Project Scheveningen at PubForum Dublin 2005, and Ericom developed a prototype for this a few years ago, but so far no one (to my knowledge) has made this technology available to the public.

Reverse seamless is primarily a client-side technology, where you make sure that a local application's window is able to open on top of the remote desktop window. The hard part is getting the integration to "feel" right. You need to make sure that the local app uses the remote taskbar and system tray, and maybe make sure that the appropriate shortcuts appear in the remote Start Menu. And then of course there's that whole file type association thing. (In theory it shouldn't be too hard to extend server-to-client file type redirection so that it works like client-to-server redirection, except in reverse. The real challenge is ensuring the application running on the client can see the file that's been clicked since there's no "reverse drive mapping" feature. Does the term "reverse drive mapping" make anyone else shudder?)

Where is reverse seamless useful?

At the end of the day, reverse seamless is not a "killer" feature. If it's not something you need, then you're probably thinking "what's the big deal?" But where it's useful, look out! These people have been asking for it for years!

The perfect use case for reverse seamless windows is when you want to deploy a remote desktop (either Terminal Server- or VDI-based), but where you still have a few applications that need to run locally on clients (media players, maybe a web browser, graphically intensive apps, etc.) The cool thing is that you can still use Presentation Server application streaming or SoftGrid or whatever to stream these apps to your desktop.

Besides that main use case, there are a few other more specialized scenarios where reverse seamless could be useful. First, it could potentially eliminate the "double hop" scenario IF the client device has the ability to connect directly to both servers. (i.e. instead of connecting to a full screen remote desktop, and then launching seamless window sessions to other servers within the desktop, you could just use the client's local ICA client to connect directly to the additional servers, and that remote seamless window, running on the client, could be integrated with the full screen remote window that's also running on the client via reverse seamless.

There could also potentially be an employee-owned PC use case, although most people would probably use an employee-owned desktop with corporate apps. But reverse seamless is certainly an option.

Is reverse seamless right for you? It depends. You have to look at your applications one-by-one and decide what delivery technology is the best way to get that app to a user. And remember, the desktop is just another application. If a use case dictates that a desktop must be local, great, then you can provide a local desktop and then provide applications either locally or remotely, again on a case-by-case basis. And if the use case dictates that a remote desktop is a better fit for the user, great, then applications can be provided either remotely (seamless into the session) or locally (reverse seamless into the session) as needed.

Citrix hasn't yet announced when the reverse seamless technology in Project Alice will make it into a commercial product. But we can assume it's coming at some point. In the meantime, does anyone know of any other way to achieve this today?

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I think RES Powerfuse does basically what you are talking about.  I was at a client last month that was using a feature RES calls "subscribed applications".  This is a quote from the feature matrix on the Powerfuse site:

"The RES Subscriber™ technology enables the integration of locally installed applications into Centralized (Server Based) Computing RES PowerFuse environments. This makes it possible to manage and control the access to local applications as well as Terminal Server applications from one central point: the RES PowerFuse Management Console. Both RES Subscriber and RES Subscriber Agent offer the integration of local applications into Terminal Server sessions."

I didn't actually get a chance to see it in action to judge its "seamlessness" but it sounded roughly like "reverse published applications".



We looked at RES Powerfuse (and Wisdom) a couple of years back, and the things that put us off were: (1) Cost and (2) Another complex third-party product on top of Windows\Citrix. 

Brian, I guess Project Alice is something Citrix have designed themselves then, and not bought in?


I am the RES Sales Engineer for the Western U.S.  The RES Subscriber product has been renamed to the RES Workspace Extender client.  RES has offered this technology to the market as part of the Powerfuse product offering.  A few weeks back I had the opportunity to present the Workspace Extender to Citrix themselves while at HQ in Lauderdale.  I am glad to see that they are engaging new ideas.

The technology is a powerful one.  Within the RES Powerfuse context the Workspace Extender offers the opportunity for the application installed to the local platform to integrate seamlessly within the user workspace. 

Examples I have seen thus far, Microsoft Communicator Client runs local (the video, the voice), while Outlook is delivered from SBC.  The automated routing software in 911 call centers is CPU intensive, and can have devastating consequences for the local device.  Delivering the routing software as a local install to the PC in the 911 center, while delivering the remaining application sets from SBC does the job.  The hospital with 3D image rendering delivered local, while the email is in SBC.  The manufacturing space where CAD is local, while Outlook and Office come from SBC.

The benefits here are two fold. 

  1. The user works seemlessly.  There is no separate window environment for the user.  The user workspace is the very same environment the user has always come to, everything is familiar.

  2. The IT professional works from a unified management console.  RES integrates Citrix, MS TS RemoteApp for W2K8, Softgrid, Thinstall, and our Wisdom product from the same console.  So, you configure the application, publish the application to all platforms W2K, XP, Vista, W2K, W2K3, W2K8, from a SINGLE MANAGEMENT CONSOLE.  Global visibility for all applications, and all user configurations within the network from the same console!

So, while some have been asking for it for years, others of us have been working with it for years.  As I am new to the working with it crowd I am inclined to joining us on this side of the line.

As I said, it is good to see that Citrix is responding to good ideas, and sound technology.  If anyone cares to have a look, drop me a line.  Thanks for the post Brian.


Besides RES subscriber, which works really cool, I've tried a free tool TSRemoteExec a long time ago. However this works only with RDP. I should be possible to write a custom virtual channel for ICA but somehow this hasn't be done already??  I still love a Full desktop everywhere...with some local apps which need local resources
Brian, how and why does Citrix let you discuss anything from/about the Advanced Products group?
Cost? Compared to Citrix? Hard to imagine anything has greater sticker shock than Citrix :)

Who is comparing cost to Citrix?  Not me!  I was talking about the cost, on top of using Citrix.  RES Powerfuse wasn't ever going to replace Citrix for us, and it was a substantial cost on top of it. 


Everything that I'm discussing about the Advanced Products group is non-NDA. I spent the day with them, and we talked about a lot of different things. Some things they showed me were future stuff, and others they showed me was more of the "inside" story as to things that are already public. So it's maybe 50/50 as to what I can write about.

As to why, well, that's the advantage of having this website I guess! We get so many visitors each month to the site, that I think I could probably knock on just about any vendor's door, reporter-style, and say "I want to write about what you're doing," and the response would be "sure!" 

That's great, we'd just want to avoid sales guys bombarding pitches of their product on the same sight.

NCD had a product that could do this in the late 90's

it just goes to show that nothing is new in the IT world

Tom Howarth 


Last Friday RES Software released a "light" version of RES PowerFuse called the Standard Edition. The Standard Edition is availble at roughly half the price of the full-blown Enterprise Editionbut but does include all the Citrix related technologies, including the RES PowerFuse Workspace Extender (formally known as RES Subscriber).

Ron Grevink. 

No excitement here so I'm going to go eat a pickle. 
Yes Powerfuse can do this for several years (4-5)
I asked my Citrix SE about this and he said the code is ready, but they aren't pushing it out because there is not enough interest.  I could really use this functionality in my environment

5 years later... Behold, 'Local App Access' in XD7 and XA6.5 FP2.