PhotoPrism, Piwigo, Lychee, Lutim, MediaCMS, Slidebox, LibrePhotos, Chevereto, ArtVenue, Fotomoto, novaGallery, PhotoStructure, Nextcloud Photos, MediaGoblin, Zoph, phpGraphy, Blue Twilight, JCDSee Web Photo Gallery, DragNDropz are some alternatives to Zenphoto.