> This means that for all practical purposes the Vivaldi source code is available for audit.
Acid test: can I build it myself and expect to see identical binaries to what they ship?
Can you do that with Firefox? Reproducible builds are pretty hard.
Fair point. Of course, to a FOSS purist, it's still not good enough, as mere source-inspectibility isn't enough to qualify as OSI Open Source, or as FSF Free Software.