I'm super excited to announce the availability of Puppet 4. It's the first major version of Puppet in almost 2 years, and there are a ton of great changes and improvements. Stephanie Stouck wrote a post that summarizes the release:
Read the release notes and install/upgrade guides carefully, especially if you haven't been tracking the Release Candidates:
Also of note is that the repositories have changed in order to keep incompatible changes from auto-updating onto your systems. Read more about "Puppet Collections", our name for these Linux-distribution-like groups of packages, in Mike Stahnke's blog post:
Please give it a try! If you file bugs, please make sure to flag them with an "Affects Version" of "PUP 4.0.0".