بدون ----- هم میشه از مخازن اوبونتو نصبش کرد
sudo apt-get install virtualbox
البته خود virtualbox تو مخازن نیست و باید مخازنش رو بهش اضافه کرد. با نرمافزار ubuntu-tweak میشه این کار و خیلی کارهای دیگه رو انجام داد
Before version 4.0, there were two editions of VirtualBox: a full binary containing all features and an "Open Source Edition" (OSE) with source code. With version 4.0, there is only one version any more, which is open source, and the closed-source components have been moved to a separate extension pack.