A third app delivery option for VDI - layering
Good article. But there is now a third choice for app delivery for hosted virtual desktops (VDI) - app layering. With this approach, apps are captured as storage-level delta differences, and dynamically combined with the gold image of the OS and each user's own persona to create a perfect desktop "stack."
As with app virtualisation, apps don't have to be installed once they're packaged as a layer - you can just assign them to any virtual desktop and they'll appear at next boot.
But layering has several advantages over app virtualisation and streaming. First, it can deliver the "last 20%" of apps that app virt cannot, including apps with kernel mode drivers (antivirus), shell integration, global hook DLLs, etc. Second, virtualised apps that run in their own sandboxes can't communicate with apps in other sandboxes, whereas layering doesn't have this problem. Third, patching is much easier with layers, as you don't have to re-package all of the sandboxed apps that need to communicate with each other like you do with app virt (e.g. plug-ins to Excel and Word).
Downside of layering is that it's only available for VDI at this point.
Unidesk (full disclosure - we're the VDI layering company)