An excellent example of open source in action is this web site itself. It is driven by the content management platform Drupal with a MySQL database, served by the web server Apache, and hosted on an Ubuntu Linux system. Site development was also done on Ubuntu. All of these technologies are open source.

Other common examples include the popular Firefox web browser and the office suite OpenOffice.

For business applications, two products are Planner for project management and Evolution for groupware integration.

This is a very small and incomplete list. There are many more open-source software packages available for a variety of applications.