Webmin is a free open source control panel (mainly for system admin tasks, not a hosting control panel).

To install webmin on Ubuntu 14.04, run

echo "deb http://download.webmin.com/download/repository sarge contrib" > /etc/apt/sources.list.d/webmin.list
wget -q http://www.webmin.com/jcameron-key.asc -O- | apt-key add -
apt-get update
apt-get -y install webmin

Now you will be able to access webmin on port 10000 via https.

https://your-server-ip:10000/