I’ve been using ownCloud for several months and have come to like it a lot. ownCloud is the fastest and easiest way to set up and control your own personal cloud. It has a good Web interface, and you can dig into the configuration files as much as you like, which are all written in PHP.

More speed with Go instead of PHP: ownCloud Infinite Scale is ready for use
Infinite Scale is a complete modernization of ownCloud 10, which has replaced PHP with Go for greater speed and efficiency.