The source code for Rijksfinancien.nl is available for reuse at GitHub (external link). Rijksfinancien.nl cannot provide support for reuse of the source code.
The source files containing data are available on this section of the site for users who want to build applications themselves or analyse the figures presented. The original open data files are available for reuse at http://opendata.rijksbegroting.nl (external link).
The data has been edited in certain ways in the interests of uniformity and reusability. These files, too, are available for reuse.