I need to give my developer access to setup a web server on my machine, rather than interfere with my environment I would like to offer him a virtual server. What software (free) can I use to do this? e.g. would http://www.virtualbox.org/ do the job? Thanks
VirtualBox, Microsoft's VirtualPC, and VMware Server are all free tools that you can use to do this. (Note that VMware Server is not the same as VMware ESX. ESX is an expensive enterprise product, where VMware Server is a free product.)
They're all pretty straightforward.