1. Mozilla Firefox
Firefox in often pre-installed in most Ubuntu derivatives. If not, it can be easily installed from the standard repository.
sudo apt-get install -y firefox
2. Google Chrome
wget -q -O- https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo apt-key add - sudo sh -c 'echo "deb http://dl.google.com/linux/chrome/deb/ stable main" > /etc/apt/sources.list.d/google.list' sudo apt-get update sudo apt-get install -y google-chrome-stable
3. Opera
wget -q -O- http://deb.opera.com/archive.key | sudo apt-key add -
sudo sh -c 'echo "deb http://deb.opera.com/opera/ stable non-free" > /etc/apt/sources.list.d/opera.list'
sudo apt-get update
sudo apt-get install -y opera
Troubleshooting
1. Duplicate Errors after apt-get update
Duplicate Errors will be thrown if a source entry exists in more than one file.
One solution it to remove the newly created entries, e.g.
sudo rm /etc/apt/sources.list.d/google.list
References
1. Firefox Home: http://www.mozilla.org/en-US/firefox/new/
2. Google Chrome Home: https://www.google.com/intl/en/chrome/browser/
3. Opera Home: http://www.opera.com/