I've been experimenting with Gandi's virtual hosting service recently. In fact, this blog is now hosted on it.
Gandi have created by far the easiest hosting service I've used. The web interface allows you to buy credit, create pre-installed virtual machines and log in, all in under 15 minutes. Add the ease of Ubuntu to the mix (just one of the preinstalled images you can choose from), and commissioning times for new services are low indeed.
The hosting service is based on Xen, and allows you to dynamically change the resources your VMs can access (CPU/memory/disk), on a scheduled basis if required. It has an API which provides enough functionality for you to white-label hosting as part of your own web app.
Excerpt from Gandi's explanation of the amount of resource you can allocate to a virtual machine
Gandi's service isn't yet as flexible as Amazon's EC2, but it comes at the problem from the other end — its initial offering "just works" as an alternative hosting solution, with the added flexibility their Xen infrastructure brings to the mix. Even with all its tool support, Amazon EC2 feels like stepping into an alternate universe. I'm pretty excited about the directions in which Gandi's service will develop.
And yes, now I've told you all this, unfortunately you can't yet play with the beta service if you've not got an account already. The initial success means Gandi are closing new signups for a little time to concentrate on improving their infrastructure.
The good news is that Gandi say this is the final step before the full release of the system. I can't wait! It's so good to see innovative, high-quality internet solutions coming from Europe.