What version of Redactor.js is used?
We try to stay up-to-date with releases of redactor.js within a few weeks of release, but may trail a little further behind if we uncover issues in the upgrade or Imperavi comes out with breaking changes. We do not use the same version numbers as redactor.js.
To see the current version in use, please consult the changelog when installing Redactor. That will detail the upgrades we've incorporated. Alternatively, you can run $R.version in the developer console.