I've always been confused about V8 versioning. Breaking changes appear to come all the time in minor versions.
And there's this note from the release:
> Note: The version number 5.0 does not carry semantic significance or mark a major release (as opposed to a minor release).
So what does it mark? Why 5.0 at all then?
Major versions make more sense when you create a release based on the content. V8 is creating its releases based on time (~6 week cadence). So a 'major' version is nothing special anymore. In 4.9 we greatly expanded our ES2015 support which was huge but only incremented the minor version because of the same reason.
Disclaimer: I work on the V8 team.
Edit: By the way, sorry to derail the conversation. You guys are doing great work! I'm always excited about V8 updates because they generally mean great perf/feature improvements to both the most popular browsers and my runtime of choice, NodeJS.