Thanks for the kind offer, we'd love to have more experienced PHP devs on board, and will do what we can to make the experience as painless as possible.

Because of @Pax's very helpful efforts, devs are able to spin up their own fully-functional Docker environments with a seed database, so you can test before submitting PRs on GitHub.

I know you've found our GitHub repo too, but for the benefit of others, our stack is:

1. Postgres
2. PHP

We use Apache to serve, but that's not really important to know except for setting up, and HTML/CSS/Javascript too, but that goes without saying!

In terms of architecture:

* Everything is built around the database, and all access to the database is through a 'transactional' API layer of procedural code in the database itself.
* Much of the front-end code was originally quite naive — it's a relatively thin layer, and we put it together quickly. More recently, again mostly as the result of @Pax's direction and prompting, we've refactored things to add better separation. See this blog post for further details on the JS modularization (Require.JS) and resource versioning aspects of that:

   @@@ question 1015
   
* We have started to move away from using jQuery in the front-end code in favour of native (modern) Javascript. We don't support IE at all, and don't officially support anything other that the most recent versions of Firefox, Chrome/Edge/Opera and Safari. In practice we also make limited efforts to keep things functional on:

   1. Recent iOS and Android mobile devices
   2. Certain older versions of Chrome and FF that we know particular contributors are still using :)