It's easy : chromium (http://www.chromium.org/) is the open source project. It's licence is open source and can be found at http://src.chromium.org/viewvc/chrome/trunk/src/LICENSE?revi... it looks like a "BSD with attribution" licence. Chrome (google.com/chrome) is the "closed-source" distribution to loads of platforms (includes a few closed source components. E.g. it can play .mp3 files). It's got a standard closed source licence.

Comparison : http://code.google.com/p/chromium/wiki/ChromiumBrowserVsGoog...

There are other distributions, for example "fedora" chromium, that doesn't have any codec support. There are versions that are not release-engineered (ie. nightly builds, but still released by some distro), ...

You're missing the whole world of intensive lawyering (for the sake of it) we're living in.

Yes you can download Chromium source (which is the base for both Chrome and Yandex Browser), but actual Chrome has restrictive EULA which I linked.

Google Chrome includes a couple of closed-source components, including Flash.