Mac OS X

Just download the *.app file and put it into Applications folder

Windows

Download the *.zip file and extract it. The folder contains an executable *.exe file.

Linux/ UNIX

For these platforms, Arboreal has to be compiled from source. Either get the respective tarball or check out the source code. Additional to Java compiler, you will need JFlex which you can get from the ​JFlex homepage or as a package in your Linux distribution.