http://www.gesetze-im-internet.de/
All laws are available in XML, HTML, PDF, etc. The site also provides an RSS feed.
In addition, some enthusiasts regularily download stuff from there and apply those to a Git repository:
https://github.com/bundestag/gesetze
That way, this repository contains not only the current laws, but also the history of how the laws developed!
For the Git repository, the XML version is not used directly, but converted to markdown. This produces very readable diffs:
https://github.com/bundestag/gesetze/commit/f90e8fc8eb20f081...
Wouldn't it be cool if we could finally manage our laws of filing pull requests?