Brad Dutton has been leading a community that is continuing Gallery development. He and his team have made progress over the past year and have a stable version of Gallery 3 that is PHP 7+ compatible, contains a replacement for the old Flash-based image uploader, an updated jQuery Library and other features. They've been testing it for a year now with no problems and have released it as Gallery 3.1.0.
Good news!
Brad Dutton has been leading a community that is continuing Gallery development. He and his team have made progress over the past year and have a stable version of Gallery 3 that is PHP 7+ compatible, contains a replacement for the old Flash-based image uploader, an updated jQuery Library and other features. They've been testing it for a year now with no problems and have released it as Gallery 3.1.0.
You can download it from galleryrevival.com