Java (optional):
- Debian / Ubuntu: ``apt install default-jdk libgcj18-dev`` (or
any version of libgcj)
- - macOS or Windows: Grab a `full JDK <http://www.oracle.com/technetwork/java/javase/downloads>`_
+ - macOS: Grab a `full JDK <http://www.oracle.com/technetwork/java/javase/downloads>`_
For platform-specific details, please see below.