Hello, I've been trying to figure out how exactly some hosts like "slicehost.com" allow the client to do their own recovery, reinstalls, etc on the server. Yet other companies like Eapps, require a ticket to be submitted?
I'm looking to offer VPS hosting and am curious what software can handle this type of end-user control, as I think it will reduce support tickets alot.

HyperVM is an example of software like this, basically like a control panel for your VPS. Some hosts may require a ticket to be submitted because they manage the VPS' themselves or for whatever reason.
Virtuozzo has software like this as well, and most likely a bunch of others.

Control panels like HyperVM are good for these things, especially backups and things but most things can also be done through SSH.