OCaml 5.2.0 is still a somewhat experimental release compared to the OCaml 4.14 branch. Some of the highlights in OCaml 5.2.0 are:

• Re-introduced GC compaction
• Restored native backend for POWER 64 bits
• Thread sanitizer support
• New Dynarray module
• New -H flag for hidden include directories
• Project-wide occurence metadata support for developer tools
• Raw identifiers
• Local open in type expressions

And a lot of incremental changes:

• Around 20 new functions in the standard library
• Many fixes and improvements in the runtime
• Many bug fixes