IDEA

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

Ultimate Edition

I have a full license for my open-source work, granted a year at a time. Download the tar, untar it here, and set up a symlink:

~m/development/intellij/idea-###
ln -s idea-#### idea

During installation, it will ask where to put startup script, make it machine-specific for now to handle diff version, eg:

/home/m/development/scripts/ubuntu/case/idea

Community-edition

To install, download the (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