Akka is the platform for the next generation event-driven, scalable and fault-tolerant architectures on the JVM. Using the Actor Model together with Software Transactional Memory Akka raises the abstraction level and provides a better platform to build correct concurrent and scalable applications.

Apache Buildr is a build system for Java-based applications, including support for Scala, Groovy and a growing number of JVM languages and tools.

sbt is a simple build tool for Scala projects that aims to do the basics well.

Bowler is a RESTful, multi-channel ready web framework in Scala with a functional flavour, built on top of Scalatra and Scalate, with Lift-JSON doing the heavy JSON lifting.

specs2 is a library for writing executable software specifications. With specs2 you can write software specifications for one class (unit specifications) or a full system (acceptance specifications).

Lifty is a SBT processor for generating files associated with the Lift framework.

ScalaFX is a UI DSL written within the Scala Language that sits on top of JavaFX 2.0. This means that every ScalaFX application is also a valid Scala application. By extension it supports full interoperability with Java and can run anywhere the Java Virtual Machine (JVM) and JavaFX 2.0 are supported.

Scalate is a Scala based template engine for generating text and markup.

Scaladin tries to make easier to use Vaadin Framework with Scala programming language.

Dependency Finder is a suite of tools for analyzing compiled Java code. At the core is a powerful dependency analysis application that extracts dependency graphs and mines them for useful information. This application comes in many forms for your ease of use, including command-line tools, a Swing-based application, a web application ready to be deployed in an application server, and a set of Ant tasks. JarJarDiff is another important tool in the suite. It compares two versions of the same codebase and reports the differences in the API. It lists new, changed, and removed elements such as packages, classes, methods, and more. You can tailor the reports to focus on your public, published API versus the private, internal one. Finally, Dependency Finder has a tool for computing object-oriented software metrics that give you an empirical quality assessment of your code. Once again, you can tailor the report to focus on the metrics that you care about and adjust validity thresholds to the specifics of your project.