The syntax for specifying the base type of an enum, `enum Name < BaseType` has been deprecated. Use `enum Name : BaseType`

Properties (property, setter, getter) can now be restricted to a type with the syntax `property name :: Type`

Compiler: can run `crystal spec file:line`

Spec: `describe`, `it` and `pending` capture file and line information and that is shown at the end when there are failures (similar to RSpec)

`typeof(self)` as a macro def return type makes `self` resolve to the most specific type, not to the type where the macro was defined