Plenty of us are now becoming increasingly used to running virtual machines as a way of virtualising our IT resources, especially when running on operating systems which are not necessarily top of our favourite vendor’s support matrices (ahem Domino Administrator/Designer ahem).  Well, my personal favorite is still VMWare, and I tend to have VMWare Fusion running almost 100% of the time on my Mac, whilst others I work with have a preference for Parallels for similar tasks.  However neither is necessarily a cheap option if you need to be creating/running VMs on multiple machines or to run them on some more obscure platforms.
Enter in the OpenSource option:
Sun xVM VirtualBox software is the world’s most popular open source virtualization platform because of its fast performance, ease of use, rich functionality, and modular design.
Features & Benefits
Higher, Wider, Deeper — Sun xVM VirtualBox is available to run on a higher number of host platforms than any other virtualization platform, has wider guest platforms support than any alternative, and a deeply compelling feature set too.
Features & Benefits
Run multiple operating systems concurrently on the same computer    Â  * Hosts: Windows, Solaris, Linux, Mac OS X.
  * Guests: Support for practically any x86 based OS.Open APIs and Modular Design    Â
  * Supports both GUI and rich CLI commands.
  * COM/XPCOM interfaces.
  * Web services interface.Sun xVM VirtualBox can easily be built upon to deliver custom solutions or products, or be embedded as a component into systems.
High Performance     Sun xVM VirtualBox is highly efficient at delivering high performance virtual machines for its guests.…
A secure multi-platformed desktop.
Free and Open Source    Â  * Free as in Free Speech
     o Open Sourced under GPL.
     o Source code is available.
     o Strong community backing.
  * Free as in Free Beer
     o Binaries available for download.
     o Free for Personal Use and Evaluation.
Available direct from Sun, I’m going to give it a go…
