For those of us who don’t follow OCaml development, what’s the big story line here?
Externally visible changes: better error messages and some new optimizations. Internally there have been a lot of bugfixes and code cleanups, making it easier in the future to merge the new big features, like multicore (this does not mean that they are there yet, but things are moving at a good pace)
FreeBSD/AArch64 support is great news as well.
Does removing compiler plugins have implications for Bucklescript and js_of_ocaml?
Not really. BuckleScript is an alternative compiler backend, and JSOO works on bytecode executbales so it’s not affected by any compiler changes (its custom REPL may be affected by removal of hooks though).
I don’t think I ever used a compiler plugin in my life, everything widely used (PPX extensions, alternative backends etc.) uses newer mechanisms.
Thanks for the clarification :)