Drupal is a content management system (CMS) that is widely used, in active develpment, and also happens to be very well written. That's the "Druplicon", which looks remarkably like the guy who started it all.

A "content management system" is a computer program (or programs) that makes it easy for you to build and maintain your website. Drupal is not a program on your computer, but on the computer that serves your website. To use it, all you need is the same tool you use to view websites, i.e. a "web browser".

Here's the story about how it started and why it's called Drupal. It's very popular and used on lots of different sites these days -- here's a page of case studies.

To learn more about Drupal:

1. visit the Drupal site,
2. look at a case study by IBM,
3. track my activity within the drupal community