How to Install Latest VirtualBox on Debian Stretch 9

Installing

3. 3. Installing GDebi

   Checking/Installing GDebi Package Installer
   Because GDebi Manage All the Eventual needed Setup Dependencies

   which gdebi

   If Not there then:

   sudo apt update

   sudo apt install gdebi-core gdebi

4. 4. Installing VirtualBox

   Installing Latest VirtualBox
   First, Access the Target:

   cd ~/Downloads

   Check the Package is there:

   ls . | grep virtualbox

   (Alternatively when Downloaded with Firefox it may be into /tmp/mozilla*)
   Then use GDebi to manage gracefully the Installation:

   sudo gdebi ./virtualbox*.deb

Install VMware Player for Free on Debian:
VMware-Player for Debian.