This is a memo on how to install Owncloud 9 in Debian 8. Since the latest version of owncloud’s fork, nextcloud, is available, you may look at it as an alternative. I prefered to go with Owncloud since they provide Debian packages.
Note: Since the initial writing of this memo (which was started in August 2016 and remained un-pusblished until now), I changed my mind on my web server configuration: I switched from the Apache2 web server to Nginx, deleted the Owncloud instance and installed Pydio. I will no longer maintain this post.
This post mainly follows this following how-to: https://www.howtoforge.com/tutorial/owncloud_9-installation-on-debian_8/