It is possible to obtain console access to a Linux VPS via the standard CloudVPS Interface. This enables you to perform the same tasks that can be done from a physical server with a screen and keyboard or serial console. We are currently working with Microsoft to implement this for Windows VPSes.
The biggest advantage of this method is that it provides access in those situations in which your VPS cannot be reached via the network, either due to an incorrect setting or because the VPS has hung during the start-up process.
To offer this as a web-based solution we have opted for AjaxTerm. This software provides access to programs that run on the command line via an AJAX-based webpage. We have built an extra security layer around this to prevent cross communication between user sessions.
Because the VPSes in our infrastructure run in a cluster, the moment a session begins a check is performed to determine which physical machine your VPS is currently running on. The session is then established on the correct machine and displayed in the browser via a central interface node.
Like a physical screen or a serial console, the console of a Xen VPS only allows one session at a time. For this reason we have built in 'locking with pre-emption', which means that if a second session is opened the first session is automatically terminated so the output does not randomly appear on another screen.