Drupal is an open source (free) Content Management System (CMS) and web development environment. To many who have paid for traditional software in the past, the concept of open source is difficult to understand.
Programmers have been developing web sites for quite a while. They were always building in the same functionality over and over, logins, blogs, etc. Some developed their own templates which they used as a starting point for all their sites. Then, some programmers got together to share their common functionality, mutually building in additional features and maintaining the existing functions. Since everyone was contributing, anyone could use the project for free.
Monarch Digital is part of the community that uses and supports Drupal, the premier open source web development CMS. Over time, Drupal has dramatically grown past content management into a full-blown web development framework. Through Drupal's open architecture, developers across the world contribute and maintain modules that plug in to Drupal, providing immediate functionality, such as Twitter integration, content moderation, extensive e-commerce and much, much more.
Yes, Drupal is free, but the moral obligation of developers like Monarch Digital is to contribute back to the Drupal community, making the project and the community stronger.