I want to install VirtualBox on a fresh debian box without having to install an X-Server.
How can that be done ?
VirtualBox (both OSE as well as the free binary version) can be installed without X.
when running VMs you can run the VirtualBox X client over X11 although its not much fun unless you have a really fast network, but you can start your VMs headless using VBoxHeadless and then connect to them over the network via VRDP to get a console (useful for installations) or just using SSH.
VirtualBox is very good about that - everything you want to do can be managed using command line tools, even feeding keyboard input.
I don't have access to a Debian box right this moment, but I just checked on an Ubuntu box, and the dependencies for the virtualbox-ose package do not seem to include X. They do include several libraries for X.
So my first stab at an answer for you is to simply try:
Here is a guide with lots of help for managing a headless VirtualBox:
If you have trouble doing what you want with VirtualBox you might also look into other virtualization systems such as Xen.
yes, also phpvirtualbox is what you can use for managing them.
with it, installing client will become much easier and you can do in-browser remote desktop.
You will proabably also install virtualbox extension pack by example:
After that, start all the service or do a reboot! Any questions, commet below