As stated, I want to contribute, but I'm finding it surprisingly difficult. The project seems to be in a state of semi-abandonment, its source using technologies and dependencies from over 5 years ago, many of them now deprecated or a thing of the past (ADOdb, the old mysql extension or Smarty, to name a few).
I don't know which one is the "official" site or how to report a bug correctly. I don't even know which one is the canon source for the source code:
Sites that may be official (or not):
Four different sources, all seem legit. Gitlab has its own bug reporter, the bug report tool listed on the sites has its certificate expired. An the worst thing is that wherever you get the code from, it hasn't received a commit for a long, long time.
But anyway, I downloaded one of them, installed it and (after disabling error displaying) ran it successfully. So, what now?
How can I help? What is the state of the project and is there an updated roadmap? Is there a bugtracker with actual issues to solve? Any intention of using modern "de-facto" standards (composer, PSR, Twig, maybe even a framework like Symfony, Silex, Laravel, you name it).