Chromium is the open-source source code made by Google and allows you to be on the cutting edge of browser developments. In Chromium, several Google-related components including in-built PDF and flash players, Google Update, usage tracking and Google branding are not included.
The source code is complied at least once a day and downloads are available on the Chromium website complied for Windows, Linux and Mac. Google Update isn’t included which can be seen as a good thing as the updater runs all the time and automatically updates in the background. However, you wouldn’t be automatically up-to-date unless you use Chromium Updater which needs to be installed manually or try out one of the extensions.
Remember that Chromium could be unstable when compared the stable releases of Google Chrome. The main purpose of releasing Google Chrome’s source code was a hope ‘…that other projects can use it to make their products better, just as we’ve been able to adopt code from other open source projects to make our product better,’ in their first post way back in 2008.