Mainly the upgrade of V8. The release of v5 so soon after v4 is a special scenario prompted by the odd timing of the release of the new V8. It's worth noting th

Mainly the upgrade of V8. The release of v5 so soon after v4 is a special scenario prompted by the odd timing of the release of the new V8. It's worth noting that v5 is not an "LTS" release (that is, it won't have the same long-term support that v4 does). I believe even number releases are LTS releases.