OCaml 5

Riot assumes an OCaml 5 world.

That is not only a compiler-version preference. It is part of the product shape:

• the runtime story is built with modern OCaml in mind
• the toolchain story is cleaner when the baseline is current
• the docs get simpler when they are not forced to straddle too many historical compatibility modes

Why that is a good trade

A toolchain gets harder to explain every time it tries to preserve too many old assumptions.

By assuming OCaml 5, Riot gets to be clearer about:

• toolchain materialization
• runtime expectations
• the intended direction of package authoring

That clarity is worth a lot.

What it means in practice

For most users, this means:

• new workspaces should target OCaml 5
• local machines should be ready to materialize OCaml 5 toolchains
• older compiler lines should be treated as exceptions, not defaults

If you need to understand how the compiler is actually selected and installed, continue with ocaml-toolchain.toml and riot toolchain.