This is a fork of the now-dormant gallery2 project. The gallery code was written against PHP 5, and there are some changes in PHP 7 and 8 that were causing problems for me (as well as a bunch of warnings).
Since #26 the code supports PHP 8, although it's very possible I've missed some problems; please open an issue if you find anything!
This code is based on gallery2 version 2.3.2 (core version 1.3.0.2)
To upgrade from a stock Gallery2 installation:
FYI - Brad Dutton has revived Gallery 3 that is compatible with PHP 7. I haven't tried it, but you can download it at galleryrevival.com.