• https://vivaldi.com

• Vivaldi Web Browser 3.2 Released with Improved Pop-out Video | UbuntuHandbook

wget -qO- https://repo.vivaldi.com/archive/linux_signing_key.pub | sudo apt-key add -
sudo add-apt-repository 'deb https://repo.vivaldi.com/archive/deb/ stable main'
sudo apt update && sudo apt install vivaldi-stable