Currently I am looking at new models /theories that expand the scope and reach of the System Engineering of very big projects in the real physical world (tunnels, aeroplanes, software-systems etc, budget >15000.000.000 Euro) the imaginary world (Models) and the relation between both worlds resulting in generators /configurators that are able to maintain physical or human structures and update their behavior according to change in their environment. A higly advanced website is the website of Kent D. Palmer related to what he calls Schema Theory., this is about naming meta-systems. (what is a land-scape?).
I believe the foundation of mathematics is the foundation of philosophy and the foundation of System Design. In this case I believe the most important foundation is Projective Geometry and its new development generalized projective geometry.
Systems Theory is based on Mathematics and Mathematics is rapidly changing because of conformal theory.
I have found a huge website called http://www.quantonics.com/. On this website I have found the book The concept of Object as the Foundation of Physics written by Irving Stein. The website is about Quantum Mechanics.
Just as mr Stein I am a big fan of Feijnman and his Absorber theory which implies that the future and the past influence eachother. The first part is not accepted in common thought but explains a lot even the integration of Quantum Mechanics & Special Relativity Theory.
An interesting link on the website of Quantonics is the well-known book Zen and the Art of Motercycle-maintenance of Robert Pirsig and its successor Laila.
Robert Pirsig was convinced that Quality and Quantum Mechanics are the same issue. He wrote a special document about it called Subjects Objects, Data and Values (SODV).
When you know about Paths of Change you will see that SODV contains the same (meta-)model.