It was made using PHP in the DevelNext studio development environment.
This is one of my first projects. This is a music player with many features and its unique design. The project is in the zip archive, in new versions of DevelNext they are automatically detected, just specify the path to the file.
This is an old project and it may work unstably, errors on some new versions of DevelNext are also possible.
Official website: http://develnext.org