A closed-source browser that's built on Chromium. In 2016. Why.
From https://vivaldi.net/userblogs/entry/a-few-words-about-open-s...
> Our source code package is available here: vivaldi.com/source. This links to a copy of the Chromium source code with the changes we made to allow our HTML/CSS/JS UI to run.
> All our changes to Chromium source code are under a BSD license and hence can read by anyone. The details are explained in the the README and LICENSE files, within that package.
> In addition, all of our UI code (included in normal packages) is written in plain, readable text. This means that all parts of Vivaldi are full audit-able and open from that perspective.