The following tools need to installed on the system before a GeoServer developer environment can be set up.
Due to subtle changes in Java class libraries we require development on Java 8 at this time (although the result is tested on Java 11).
GeoServer uses a tool known as Maven to build.
Maven tracks global settings in your home directory .m2/settings.xml. This file is used to control global options such as proxy settings or listing repository mirrors to download from.