Chromium-based browsers and Tor tend to indicate which version of Chromium and Firefox they're based on respectively.
How do we find that information for Pale Moon? It's neither in the browser's About or Release Notes. http://www.palemoon.org/releasenotes.shtml
Tahr default is 25.
Xenial is 27(.6.1).
I'm in 29.4.1, Firefox