To be honest, I think Athena and X have had very little influence. X's GUI design (and the Athena widget set) was entirely derivative of the Lisa/Mac interface. The notion of a client-server GUI system -- a historic extension of Unix terminals and servers -- has largely failed and is now disuse on modern Unix systems. The idea of a customizable window server has not spread beyond X to any other major system to my knowledge. Its font subsystem, graphics subsystem, and event management was and remains astonishingly primitive. It's hard to think of anything X innovated that now appears in a modern GUI.

Despite what the random Wikipedia contributor implied, neither MATLAB nor Maple have any historical relationship with X Windows or Project Athena. It is a huge stretch to say that Athena invented the concept of per-course educational and research software given that Apple had been doing that nearly a decade before, and indeed had built its entire business model on the concept. And the precursor to Jupyter notebooks was Mathematica, full stop. Mathematica invented the very concept of the interactive notebook, and it did so on NeXTSTEP.