VirtualBox is a cross-platform virtualization application. Basically, it allows you to run two (or more) operating systems at the same time, on the same computer. This way, you can run a program specifically written for another OS (for example, run Windows software in Linux) without having to reboot your computer.
VirtualBox is available under the General Public License (GPL), which means it’s free, as opposed to it’s rival, VMWare Workstation witch is only freely available for non-comercial use.
Version 4.3.16 has been released on 09-09-2014 and comes along with lots of bug fixes and items added (full Changelog).
Howto install VirtualBox 4.3.16 on Ubuntu 14.04
Add the official VirtualBox repository for Ubuntu; open-up a terminal and type:
sudo add-apt-repository "deb http://download.virtualbox.org/virtualbox/debian trusty contrib"
Get the keyring:
wget -q https://www.virtualbox.org/download/oracle_vbox.asc -O- | sudo apt-key add -
sudo apt-get update; sudo apt-get install virtualbox-4.3
Howto install VirtualBox 4.3.16 on Fedora 20
Add the Fedora repo file:
sudo wget http://download.virtualbox.org/virtualbox/rpm/fedora/virtualbox.repo
Install VirtualBox (the letters V and B are capitalized):
sudo yum install VirtualBox-4.3