Ghost CMS is ultra light weight and somewhat easy to install. You can install it direct at digitalocean.com or you can try ghost.org where they take care of the hosting headaches but cost around $19/month.
Ghost vs Wordpress
Ghost seems promising to have the ability to challenge Wordpress for the top CMS out there but what makes Ghost different is the opposite of what Wordpress is. Wordpress started as a blogging platform but developed more into a fully flexible CMS where Ghost focuses more on the aspects of blogging and writing.