virtualbox.org

I could see in the VirtualBox manual that VRDP is supported.

I would like to know what are the possibilities of configuring a VirtualBox server to host machines where remote connections will be make to those machine but not having the need for a host operating system for a VistualBox GUI.

I could see that VirtualBox has a non-GUI manager but it's unclear to me what are the host specification to start using this.

Is it a basic Linux distro enough and required? Can it be DOS based?

Thank you for any replies.

Dos no. Linux OK. windows XP or newer. Apple OSX. Solaris.
Not all version of linux works directly. See this link for list.

Asked before: http://forums.virtualbox.org/viewtopic.php?f=1&t=18195