Clirr is a tool that checks Java libraries for binary and source compatibility with older releases. Basically you give it two sets of jar files and Clirr dumps out a list of changes in the public api. The Clirr Ant task can be configured to break the build if it detects incompatible api changes. In a continuous integration process Clirr can automatically prevent accidental introduction of binary or source compatibility problems.

Scala.js compiles Scala code to JavaScript, allowing you to write your web application entirely in Scala!

specs provides a BDD framework for the Scala language

IntelliJ IDEA is focused on raising your productivity by providing instant and clever code completion, on-the-fly code analysis, easy project navigation and reliable refactorings.

Rehersal is a testing framework for Scala, intended as an easier-to-use replacement for SUnit in the standard library.

Codacy is an automated code review platform for Python, Ruby, PHP, Java, JavaScript, Scala, C++, SWIFT and mode programming languages.

Users can check code for security and duplication issues, accuracy, complexity, coding style and other metrics. The platform also parses logs from code coverage tools and presents the evolution of code coverage side by side with the other software metrics. Codacy is configurable, allowing code patterns to be enabled or disabled. Codacy integrates with GitHub, Bitbucket, JIRA, YouTrack, Heroku, HipChat and Slack. It also offers an Enterprise version that runs in the clients' servers and integrates with Jenkins, GitHub Enterprise, Bitbucket Server and GitLab.

Lift is an expressive and elegant framework for writing web applications. Lift stresses the importance of security, maintainability, scalability and performance, while allowing for high levels of developer productivity.

ScalaCheck is a powerful tool for automatic unit testing of Scala and Java programs. It features automatic test case generation and minimization of failing test cases. ScalaCheck started out as a Scala port of the Haskell library QuickCheck, and has since evolved and been extended with features not found in Haskell QuickCheck.

Apache Camel is a powerful open source integration framework based on known Enterprise Integration Patterns with powerful Bean Integration. Camel lets you create the Enterprise Integration Patterns to implement routing and mediation rules in either a Java based Domain Specific Language (or Fluent API), via Spring based Xml Configuration files or via the Scala DSL. This means you get smart completion of routing rules in your IDE whether in your Java, Scala or XML editor.

NeoDatis ODB is a very simple Object Database that currently runs on the Java, .Net, Google Android, Groovy and Scala.