Eight years ago I sat in a hotel in Dublin and listened to Jeroen van de Kamp and Dennis Damen talk about a tool they were building called "Project Scheveningen," something more commonly known as "reverse seamless windows." You all know what seamless windows are, right? It's where you have a local desktop with your start menu and app windows and which you mix in with one or two remote windows which run "seamlessly." (Think of it like remoting a single application window instead of the whole Windows desktop.) Seamless Windows is built into every VDI and RDSH-based product on the market (well, except VMware Horizon View). Heck, even the out-of-the-box Microsoft supports the feature with RemoteApp.
"Reverse" seamless windows is just like that, except flipped. With reverse seamless windows you run a full remote desktop (with RDSH or VDI), complete with remote start menu and task bar and everything, but then you mix in a few windows from some Windows apps running locally on your client device. So you essentially have "holes" (for lack of a better word) in your remote desktop which let local apps shine through.
The use case for reverse seamless windows is for apps which don't work well over HDX or RemoteFX. (So maybe apps like unsupported VoIP clients or anything else that's best run locally.) The idea is that one or two of these "problem" apps don't have to cancel your whole virtual desktop project, rather, you just continue to run them locally on a laptop and show them to the user in their remote desktop via reverse seamless windows.
So this has been something that's been on the horizon since 2005. In 2008 I visited Citrix's Advanced Products Group in Australia and got a sneak peak of Citrix's reverse seamless capabilities which they were calling "Project Alice" at the time. In the comments of my article about Project Alice, I learned that RES already had a reverse seamless product on the market (originally called "RES Subscriber," then renamed to "RES Workspace Extender," it eventually because known as "RES Virtual Desktop Extender" or simply "RES VDX" which you can buy as a standalone product for $15 per user).
Turns out that RES was the first company to commercialize reverse seamless windows and filed a patent on the functionality way back in 2001, so that pretty much put an end to Citrix's Project Alice. Actually, that pretty much put an end to most conversation about reverse seamless (except for a little AppDetective versus RES flare up in 2011).
Citrix licenses RES's patents, releases reverse seamless
I hadn't thought about reverse seamless for a few years until Citrix Synergy last month when Citrix announced that reverse seamless (or "local application access" as they're calling it) would be a feature of XenDesktop 7 and XenApp 6.5 FP2. (Citrix's Derek Thorslund blogged about it yesterday.)
I asked Derek whether Citrix had licensed RES's patents and whether that was the cause of the delay. He confirmed that yes, Citrix did license the patents from RES (something else I missed from 2011), but that the technology is all their own. He also explained that they actually released the technology as GA to Citrix Service Providers last year, and that the Synergy announcement is just the first time it's being incorporated into products for enterprise customers. But now Citrix feels confident that reverse seamless meets their level of security and reliability, and so it's available to everyone.
So while no longer ground-breaking, it's certainly great to finally have reverse seamless as an (albeit "Platinum") option.