[phforms]

I am not sure if this is what you mean, but the original UCBLogo (which I think is used in the Turtle Geometry book) is still alive and maintained[1] (not by the original authors, but Brian Harvey seems to chime in every now and then) and it does run well on modern computers.

Now that I think about it, Logo seems to be pretty much a livecoding environment (not surprising given that it is a Lisp, but with less parentheses). You can define and edit functions from the REPL while the program continues with the same state, the same canvas. You can even pause e.g. a running procedure that draws a polygon, rotate and move the turtle and then continue the polygon procedure with that new state (at least this is possible with UCBLogo).

[1]: https://github.com/jrincayc/ucblogo-code

[taeric]

It is indeed what I had in mind, I was amusingly ignorant that this was being maintained. Humble apologies on my end! Edit: And thanks for correcting me!