I briefly looked at their website recently, and it looked to me like Penrose just renders the diagram interactively as a webapp. I didn't see a "compiler" that

I briefly looked at their website recently, and it looked to me like Penrose just renders the diagram interactively as a webapp. I didn't see a "compiler" that would translate the diagram code into a standalone PDF/PNG file that would be easy to include in a LaTeX document.