The Evolution of Lisp (1993) [pdf]
I’ve always thought it unfortunate that fexprs were dropped for macros in lisp. For a language that touts homoiconicity and first class functions&#x2F;objects, it feels strange that macros aren’t first class.<p>My understanding is that fexprs have some perfomance problems over macros, but I’m not really sure why or if the state of the art has advanced since then.<p>A really interesting evolution of lisp is Shen. The license is terrible and I seriously doubt it will ever achieve widespread use. And while the idea of a kernel lisp sounds great, in practice I doubt that it actually works.<p>The performance trade-offs that you’re going to need to make become very unclear when you have a language that can run on A python, CL, js, or whatever runtime. The JVM is successful because it unifies language and implementation, instead of fragmenting it further like Shen does.<p>Racket is the clear horse to pick in this race, I think. Hopefully Racket on Chez will improve the performance to close to that of native binaries. If so, I really think that it would be the last piece of the puzzle.