Wordpress is the CMS behind approximately 28% of all websites. It is open source software with a large open source community, and it also has a large ecosystem of paid-for plugins that can extend the platform to be useful for any number of applications.
You may be more familiar with Wordpress as a blogging or publishing platform, but it’s also powerful as a general Content Management System. Right out of the box and with the addition of some plugins, Wordpress does a lot of things right. SEO is largely taken care of, performance is maximized, and the user system and permissions are solid and ready for people to start working on content. There is also a wealth of mature themes that are an effective way to get to a polished website quickly, and that are mature in terms of responsive code so that your site is extra-accessible for mobile users.
Black Antelope is a development partner of Pantheon, which is an excellent Platform as a Service (PaaS) solution for developing, hosting and scaling Wordpress and Drupal sites.