I wonder how much of Racket's improvement over time really has to do with underlying changed to GNU Lightening (the library that underpins its JITing). Also, th

I wonder how much of Racket's improvement over time really has to do with underlying changed to GNU Lightening (the library that underpins its JITing). Also, the interpreter and benchmarks look like they inherently single-threaded, so even though the server hardware looks beefy compared to the MacBook, it's really only using one of thoses (probably slower) cores. There are Scheme and CL implementations that make it easier to write code that parallelizes easier than is possible in Racket -- so anything beyond simple apples-to-apples code like this benchmark would show very different results.