The advantages of using Open Source-software are clear: the software use is for free and everyone can modify, expand and improve the software. There are big communities for the major Open Source-software projects. These communities maintain the software which means that the software continously improves. Also security aspects are taken seriously.
An extra advantage is that tailor-made solutions are available to solve known problems. The software does not need to be researched in-depth because other developers already solved particular problems. The results can easily be re-used. This minimizes the software development time.
Some projects in which the CMS System Drupal has been used: