I have an Ubuntu Server 14.04.
Is possible to install VirtualBox in this Ubuntu Server just using a command, without GUI?
VirtualBox can be installed on the command line, directly from the Ubuntu repositories. This will install VirtualBox version 4.3.10:
sudo apt-get update
To update your package management system to use the most current packages. Followed by:
sudo apt-get install virtualbox
To install the main package and its dependencies.
After that I'd recommend getting the VirtualBox guest additions iso, with:
sudo apt-get install virtualbox-guest-additions-iso
The guest additions are required to ensure smooth running of your guest OS, when you build virtual machines.
It is normally necessary to obtain a VirtualBox extension pack to use all of the features of virtualbox, here is the virtualbox old builds download page, the file is located under version 4.3.10 - Extension Packs - All Platforms. Alternatively the direct download link is here.
You can install VirtualBox using
apt-get, without a GUI:
sudo apt-get update; sudo apt-get install virtualbox
From there, you will need to read the VirtualBox manuals for command-line instructions. You will probably want to configure them with an RDP server so that you can access them graphically (but remotely).