Drupal is a wildly popular award winning open source social publishing system which powers the website of the President of the USA, many large media sites around the world (e.g. France24, MTV UK) as well as the sites of thousands of companies (e.g. AT&T, Ahold), Communities (e.g. Amazee), NGOs (e.g. Amnesty International) and other organizations.
Drupal combines the functions of a content management framework, social publishing and content management system. A major distinguishing feature of Drupal is that allows many pieces of information (called nodes) to be stored in a database and combined to produce web pages dynamically when they are called up.
It comes with on board tools for Search Engine Optimization such as Volacci's SEO Checklist, hundreds of different themes and thousands of community contributed modules.
Anolim provides development, support and IT infrastructure (e.g. hosting) services for Drupal.