IDEA

IntelliJ IDEA is an excellent IDE for Java and Scala. The Causam team uses it, I'll follow suit.

To install, download the Community-edition (Java/Groovy/Scala/Android) IDEA linux tarball from the website.

cd development/intellij
wget https://www.jetbrains.com/idea/download/download-thanks.html?platform=linux&code=IIC
untar ideaIC-2016.2.1.tar.gz
mv idea-IC-162.1447.26 idea && cd idea
bin/idea.sh

The installer will ask you many questions to get things set up. Make sure to download Scala support, and set up the startup script here:

~m/development/scripts/idea