Historical tidbit: Pizza is the precursor to Java's own generics implementation (introduced in Java 5), both were written by Martin Odersky who then went on to create Scala.
- Generics (aka Parametric polymorphism)
- Function pointers (aka First-class functions)
- Class cases and pattern matching (aka Algebraic types)
13 years, and only it's three features has made it into Java
I wish Sun found a way to transfer the Java trademark to Odersky before dying.
Scala has so many nice features that companies prohibit because the language isn't called "Java".