OwnCloud provides ready-to-deploy packages for popular Linux distributions such as Debian, Ubuntu, Fedora, RedHat Enterprise Linux, CentOS and openSUSE. Refer to http://software.opensuse.org/download/package?project=isv:ownCloud:community&package=owncloud to get the right repo info.
Below the quick install for Ubuntu server 14.04.
Install the Owncloud repository for Ubuntu 14.04 on your system:
sh -c "echo 'deb http://download.opensuse.org/repositories/isv:/ownCloud:/community/xUbuntu_14.04/ /' >> /etc/apt/sources.list.d/owncloud.list"
Add the repository key to apt
wget http://download.opensuse.org/repositories/isv:ownCloud:community/xUbuntu_14.04/Release.key apt-key add - < Release.key
Then just update and install:
apt-get update
apt-get install owncloud