This software gets better with every release. I use it on a Mac to run Windows XP (to remind me how good the Mac really is), Ubuntu, and various web development appliances such as LAMP, Joomla, and Mediawiki. With the exception of the odd delay that occurs between new Ubuntu releases and the VirtualBoxHost Additions playing catch-up, I rarely have a problem with the software.

What I really like with the new 4.1.0 version (having played with it in Beta) is the ability to clone a virtual machine with just a couple of mouse clicks. This means I can use my own "standard appliance" customised to my own needs that I can replicate for use on new projects. This will save me loads of time in the future.

If I have any gripe it is that Bridged network mode must be bound to a specific interface on my Mac - which is a pain because I frequently switch between wired and wireless working depending on where I am at the time.