VMTN Blog

Tom Howarth has a new blog, PlanetVM, but you may be familiar with Tom if you've been involved with either VMware Communities or the Citrix/SBC worlds for a while. Today on the Roundtable podcast (notes to come), in between expressing some strong opinions on VMware View, he mentioned the ridiculously large VDI deployment he's working on. (What's larger than ridiculous?) All this is a roundabout way of signaling you to pay attention to what Tom has to say, even if he can't spell virtualisation.

Tom's started a series of posts on application virtualization, such as VMware ThinApp, which we've recently updated to ThinApp 4.0.1.  The good folks at virtualfuture.info have a nice application virtualization comparison chart. (Matthijs & Sven, where's that update?)

Here's part one of Tom's series. Application Virtualisation - Part 1 | PlanetVM.

What is Application Virtualisation?

The idea behind application virtualisation is relatively simple in that an application runs on your desktop without ever having installed it. However, unlike using Terminal Services, the virtualised application executes locally, using local resources (e.g., processor, memory, disk, and network card). In other words, the application runs, saves data, prints, and acts as if it’s installed locally even though it is not. On top of this, you can run multiple versions of the same application on your desktop without conflict, and run conflicting applications like different versions of Access or Outlook with out conflict—again, with all the applications executing locally – and not as “screen scrapes” from a remote Terminal Server.

The basic concepts of application virtualisation are that the application executes on the local machine using its resources, but is not allowed to modify anything. Instead, it runs in a small virtual environment that contains the registry entries, files, COM objects, and other components that it needs to execute. This virtual environment acts as a layer between the application and the OS. The virtual layer is very “light” (generally only a couple megabytes of memory) and loads just prior to the application loading.