To install the latest build of Firefox (Aurora), or one of the release, beta, extended support release (ESR) versions, use instructions from < Basically you choose your distribution (stable, testing, unstable), choose Firefox, choose the version, then add a string in `/etc/apt/sources.list`, then update the packages list. Then run
sudo apt-get update
sudo apt-get install -t experimental firefox
You would also possibly need to install package `pkg-mozilla-archive-keyring` for APT not to complain about untrusted sources.