Hi, thanks for sharing. My idea is to replace the fewest possible elements in web technologies and stick with current browsers because this makes the most sense in terms of feasibility (at least for now). This way integration is less of an issue and can be handled visually with a simple rectangular container. As long as my building blocks are pieces of HTML, CSS and JavaScript, these new websites will always be compatible with current websites. I just want to fundamentally alter how HTML and CSS work and JavaScript is a perfect tool to achieve just that.

Constraint recalculation is actually not the most difficult problem if you use JavaScript. Yes, you need to "listen" for changes but even if I need to recalculate the entire layout as a result it can be done under a few milliseconds. This is a higher refresh rate than 120 Hz with low computing power and medium complexity websites which is insane if you consider that we are using a high level language and the browser is not even optimized for this type of layout system.

Thanks also for the links. Just a quick note, do you happen to work with HSB/HSV also? Many designers prefer HSB over HSL but unfortunately the web only supports HSL natively.