ImpressCMS is an open source Content Management System (CMS) for building and maintaining dynamic web sites, written in PHP and using a popular open source MySQL database system for content storage. ImpressCMS is extremely useful for managing online communities because it has the ability to create user groups and assign permissions for managing content to each different group. It is fairly easy to install ImpressCMS on an Ubuntu 14.04 VPS. The installation process should take about 5-10 minutes if you follow the very easy steps described below.