- Support for read-only BigArrays (or sections) : we're starting to switch to just using bytes/string in OCaml 5+ now, since the larger allocations go into malloc'ed pools and do not relocate, so they can be used as part of an FFI (without the Bigarray C value overhead)
- More support for floating-point numbers (exceptions, representation exploration): OxCaml has some of this now! https://oxcaml.org/documentation/miscellaneous-extensions/sm...
- Syntax for extended BigArray indexing: now supported in OCaml https://ocaml.org/manual/5.4/indexops.html#ss:multiindexing
- LaCaml remains too low-level (non-functional) and unreadable: still remains the case, but OxCaml's got initial support for SIMD https://oxcaml.org/documentation/simd/intro
- BigArray and floating-point I/O remains difficult (we would like: I/O to channels, efficient representation retrieval): much easier now with OCaml effects to build custom fast serialisers (see https://github.com/ocaml-multicore/eio)
- Native top-level: ocamlnat is (I think) shipped in OxCaml, but you can also run a wasm toplevel