Scala 2.13 is the latest minor update of the Scala programming language. Despite looking like a minor bump in the version number, this release is much more important than it might appear. 

The reason for this is that its main focus is the reworked collection library, which is going to replace the current version introduced in version 2.8 and slightly redesigned in version 2.9.

The new collection framework is here to stay in Scala 2 and also will become a part of Scala 3.

As it is mostly a library release, the language itself is not changing a lot as compared to the previous version. Apart from the collections, the new version improves on three aspects:

• Minimizes the core library
• Speeds up the compiler
• Improves user-friendliness

These details are outside of the scope of this book and we will not discuss them further. 

Besides that, there is an addition of literal and singleton types, which we will discuss in detail in Chapter 2, Understanding Types in Scala, and a few minor changes to the standard library which we'll look at next, before diving into the sea of maps and lists.

Eager to look into the future? We'll take you there!