Ubuntu is a Debian-based Linux operating system, with Unity as its default desktop environment. It is based on free software and named after the Southern African philosophy of ubuntu (literally, "human-ness"), which often is translated as "humanity towards others" or "the belief in a universal bond of sharing that connects all humanity". According to some metrics, Ubuntu is the most popular Linux distribution.
While Chromium team ppas won't release new versions of Chromium browser, Alex Shkop will try to maintain more-or-less fresh releases of Chromium. Two PPAs were built for Chromium stable and Chromium development version. Install Latest Version of Chromium: For now, two PPAs only provide packages for Ubuntu 12.04.
To add Chromium Stable PPA (currently it's version 21):
sudo add-apt-repository ppa:a-v-shkop/chromium
To add Chromium Dev PPA (currently it's version 23):
sudo add-apt-repository ppa:a-v-shkop/chromium-dev
After added a PPA, update your repository and install Chromium:
sudo apt-get update
sudo apt-get install chromium-browser