I wouldn't say it's really sophisticated tooling. Many basic editors support visual whitespace in one form or another. Some insert a semi-opaque character in pl

I wouldn't say it's really sophisticated tooling. Many basic editors support visual whitespace in one form or another. Some insert a semi-opaque character in place of tabs/spaces, and others show rulers. F# is whitespace sensitive, so you need to stick to correct tab sizes anyway, and it becomes quite readable. For types, you can also add `class`, `interface`, `struct` at the start and `end` on the correct indentation after its definition to show a clear boundary. type X() = class member this.X = ... end