From a language point of view, the main difference is that Elixir has macros. Used judiciously they are a good tool for abstraction and can provide some nice AP

From a language point of view, the main difference is that Elixir has macros. Used judiciously they are a good tool for abstraction and can provide some nice APIs. As other people have said, there are no big new ideas in Elixir, it's just a well executed design in all the details. It also has the advantage of the tooling having been built from the ground up to current state of the art. As such, it is lovely to use. The standard library benefits similarly. For example the '|>' operator in Elixir benefits from the fact that the standard library has a consistent argument order.