VMWare has strengthened its client-side technology by acquiring application virtualization vendor Thinstall. The deal isn't a huge surprise, as VMware's two main competitors both have an app virtualization side already. But it demonstrates that VMWare takes the desktop market seriously.
Although VMWare has sold desktop products for years, these are all based on the same hypervisor technology as its servers, requiring that multiple OSs are installed. Rather than a complete OS, app virtualization gives each application its own virtual copy of the Windows registry and other custom settings. This means it only works with Windows (XP and Vista), but compared to OS virtualization it can save on system resources and (often) software licensing costs.
Thinstall's main innovation was to separate app virtualization from software streaming. Sold by Citrix, Microsoft, Altiris and Endeavors Technologies, streaming requires client-side software and a management server to control the virtualized apps and their associated virtual registries. The Thinstall technology is superficially simpler, bundling each application with its associated DLLs and settings into a single executable file. That makes distribution easy, as it turns Windows applications into the desktop equivalent of virtual appliances, able to run without installation. Users can carry their apps around on a USB drive and run them on any Windows PC.
The downside of Thinstall's approach is more complicated management, at least compared to streaming, as there's no built-in way to see who is using which applications or whether they're patched. Thinstall got around that by partnering with network management vendors, notably LANDesk, which re-sells the Thinstall product and has integrated it into its own management software. LANDesk says that their OEM agreement isn't affected by the acquisition, but with VMWare also using virtualization management as its main differentiator in the hypervisor space, some tension between the two seems likely.
Thinstall's technology isn't unique anymore. In November, Microsoft upgraded its streaming product to allow what it calls standalone delivery, which accomplishes much the same as Thinstall. It also renamed the software Microsoft Application Virtualization to emphasize that it can be used in non-streaming architectures. On the same day, it launched Hyper-V server virtualization, a direct assault on VMware's core business.
The other big competitor is Citrix, which acquired VMWare competitor XenSource in November and developed a streaming system in-house, viewing it as the next generation of thin client technology. Streaming essentially does for thin clients what Ajax does for the Web " namely, take advantage of client-side processing and storage. Citrix also has a technology that it calls OS Streaming, but this is really closer to storage virtualization than app virtualization. Based on products acquired with Ardence, OS streaming is a SAN for workstations, linking diskless desktops to remote storage through Gigabit Ethernet. That gives it most of the same strengths and weaknesses as traditional thin clients: simpler management and greater IT control, but no support for remote or laptop users.
The big three virtualization vendors aren't the only players in app virtualization. As well as Altiris and Endeavors, there's AppStream, which targets Web-based SaaS providers. And the vendor most like Thinstall is probably RingCube, a startup that applies virtualization per-user rather than per-application. Instead of giving each app a dedicated VM, RingCube creates a single VM that's shared by all the user's applications and data.
The shared VM ought to result in better performance when more than one app needs to be virtualized, but unlike Thinstall (and streaming) it doesn't help resolve application conflicts. RingCube originally pitched its technology at home users as the MojoPac, a USB drive that could hold a user's entire desktop. It has since moved into the enterprise market, trying to persuade companies to ditch laptops and issue users with flash drives instead.
But the real dark horse in desktop virtualization could be Google. In May last year, it bought GreenBorder, an app virtualization startup focused on security. GreenBorder's implementation was similar to RingPac's in that all virtualized applications shared a single VM, but it was aimed at isolating untrusted files downloaded from the Web or received via email. Google discontinued the products for new customers shortly after the acquisition, and hasn't said what (if anything) it plans to do with the technology.