Scala 3.0, also known as "Dotty," has several new features that provide improvements in performance, safety, and expressiveness. Some of the most notable new features include:

Union Types: Scala 3.0 introduces union types, which allow a variable to have multiple types. This feature enables developers to write more concise code and improves the type safety of their programs.

Type Aliases: Scala 3.0 introduces type aliases, which allow developers to define a new name for an existing type. This feature can improve code readability and make it easier to refactor code.

Givens: Scala 3.0 introduces givens, which allow developers to define implicit values and parameters in a more concise and readable way. This feature improves the expressiveness of the language and makes it easier to write generic code.

Extension Methods: Scala 3.0 introduces extension methods, which allow developers to add new methods to existing types without having to modify the original code. This feature improves code organization and can make it easier to write reusable code.

Multiverses: Scala 3.0 introduces multiverses, which allow developers to write code that can run on different versions of the Scala compiler. This feature improves the flexibility of the language and makes it easier to maintain backward compatibility.

These are just a few of the many new features introduced in Scala 3.0. For more information, you can check the official Scala documentation.