There’re two types of Opera installations on Ubuntu, static and shared. The static version has the built-in Qt library, it’s a larger download, and it looks ugly with Unity. The shared version uses the Qt installation on your system and it’s well integrated with the system.
The recommended way to install Opera Browser in Ubuntu is using the official repository. Here’s the howto in Ubuntu 13.04 Raring, 12.04 Precise.
1.) Press Ctrl+Alt+T to open terminal, copy and paste this command and hit run to add the repository:
sudo sh -c 'echo "deb http://deb.opera.com/opera/ stable non-free" >> /etc/apt/sources.list.d/opera.list'
2.) Download and install the key:
wget -qO - http://deb.opera.com/archive.key | sudo apt-key add -
sudo apt-get update
4.) Finally install Opera (shared version) via:
sudo apt-get install opera