AlphaUserPoints is a User Points System component for Joomla! 3.x. It exists since many years but the developer (Bernard Gilly) has ended the work on it in January 2016.
jDownloads supported since some years this component with a few special plugins.
But AlphaUserPoints is no longer available on the manufacturer's website. However, since the component for jDownloads AUP plugins is needed, it can be downloaded here until further notice. It is the last published version 2.0.4 from 17. December 2015.
I hope someone will continue the work on this excellent component.
Important: I can not give any support for this extension!