If you’re looking for an home automation software, you will find a lot of projects. There is a huge interest in this area and a lot of developers working on different projects. Many focus on the visualisation. While it is important to have a good user interface, the main focus of an automation system should be it’s backend.
One project I really like is Home Assistant. It uses a very clean backend/frontend separation.You can easily add your own user interface by just using its web API. It is written in Python. That makes it easier for me to add missing functionalities.
An architecture based on Home assistant could look like this:
KNX isn’t supported out-of-the box in the current Home Assistant release (June 2016). However, I already did some programming and will work on integrating it into the official Home Assistant release.