I am using PhpStorm as my development tool for Piwigo plugins and themes. I just did a google search a few years ago and came across this development tool. It has a lot of functionality and if you buy it for personal use it is not that expensive. Fortunately you can...
Piwigo theme development documentation, consist of one page of information explaining the structure and content of theme files. This documentation is not extensive, but enough to help understanding themes created by others, which you can use as base. I started for...