Comment by infinite8s

Folk.computer (https://folk.computer) is an open source version of DL-like system, and even though the code uses TCL it's pretty easy to reimplement any bits you see in the DynamicLand archives (I've done this). For example, the code in the video here https://dynamicland.org/archive/2022/Knobs can be 1-1 translated into TCL and it works the same.

If you really wanted to play around with similar ideas it doesn't take a needing to do a full reimplemention of the reactive engine.