From the website:
Scala. Akka. Simple.
A 100% open source, integrated distribution offering Scala, Akka, sbt, and the Scala IDE for Eclipse.
The Typesafe Stack makes it easy for developers to get started building scalable software systems with Scala and Akka. The Typesafe Stack is based on the most recent stable versions of Scala and Akka, and provides all of the major components needed to develop and deploy Scala and Akka applications.
Go ahead! You need something new to put on your new, shiny 5TB disk drive. 😉