Lightbend will decommission activator by the end of 2017. So, it's better to use Giter8 templates to start initial Play, Scala, Akka, and more, based projects.
For more information, read https://www.lightbend.com/community/core-tools/activator-and-sbt.
To use this new approach, install sbt 0.13.13 (or higher), and use the sbt new command. To see all available Giter8 templates, go through the GitHub URL https://github.com/foundweekends/giter8/wiki/giter8-templates.
Here's an example:
To create a basic simple Scala project:
$ sbt new <path-to-your-new-project>/scala-app scala/scala-seed.g8
To create a basic simple Scala and Akka project:
$ sbt new <path-to-your-new-project>/scala-app akka/akka-scala-seed.g8
To create a basic simple Scala, Akka, and Play project:
$ sbt new <path-to-your-new-project>/scala-app playframework/play-scala...