I don't think Ceylon is really in the same category as OCaml. OCaml is closer to F# and Haskell. Ceylon is probably closer to Kotlin.
Kotlin basically has the Java type system with a few extensions, but no substational changes.
Ceylon has its own type system that draws heavily from the FP/ADT style of thinking. It's not OCaml (nor does it want to be), but it's also not Kotlin.