Why does SBT's Scala (2.10) not include Akka?

Question

I downloaded Scala 2.10.2, unpacked it and run Scala command, I can successfully import akka._.

In another experiment, I create an sbt project with the following line in build.sbt:

scalaVersion := "2.10.2"

A source file import akka._, and sbt complains "akka not found".

What is the difference betwen SBT's Scala 2.10.2 and the one on Scala website? And why does the official Scala already include Akka library, but SBT's Scala does not?

Answer 1

Akka is a part of the Scala Distribution (the zip you downloaded) but not the Scala Standard Library — which is what you get in SBT.