Over the past few years, the range of Type 2 hypervisor options has expanded such that most client operating systems, including Windows, Mac OS X, Linux and Solaris, can be outfitted to host an x86-based guest environment. The SBC and VDI approaches to desktop virtualisation are also cross-platform friendly, as remote desktop clients are available for most client operating systems as well.

Client-side virtualisation products place an added hardware resource burden on desktops and notebooks, however. In particular, RAM requirements for machines that host virtual desktop instances are greater. Similarly, not all applications run happily in a virtualised hardware environment, a limitation most likely to materialise for graphics-intensive applications.

Finally, just as with the nonvirtualised user-controlled system approach I laid out above, the fact that both SBC/VDI and client-side virtualisation run under a host operating system makes it difficult to exorcise issues of trust and security when that host is managed outside the domain of company administrators.

Looking forward, I expect to see support for much stronger isolation between multiple operating environments running on a single-client machine improve as Type 1 hypervisors begin to ship on notebooks and desktops. Citrix and VMware have both discussed plans for embedding “bare-metal” hypervisors in future notebooks, which should help resolve issues around deploying trusted, closely managed guest environments alongside user-controlled environments.