A safer, faster, and more stable web browser
Chromium is the web browser that Google Chrome is built on. It is meant to feel lightweight (cognitively and physically) and fast. When released, it brought a sandbox security model, minimalist user interface, and tabbed window manager that many other browsers have since adopted.
How Google uses Chromium
Most Googlers use Chromium in their daily work and its Developer Tools are a major part of web development on products throughout the company.