Here is an implementation for Qt/QML that we use at Ableton: https://github.com/AbletonAG/aqt-cassowary https://github.com/AbletonAG/aqt-cassowary Edit: Anyon

Here is an implementation for Qt/QML that we use at Ableton: https://github.com/AbletonAG/aqt-cassowary https://github.com/AbletonAG/aqt-cassowary Edit: Anyone interested in modern implementations and participating in the community of library implementers and users can check this website: http://overconstrained.io/ http://overconstrained.io/ :-)