Jar Jar Links is a utility that makes it easy to repackage Java libraries and embed them into your own distribution.

ReFit Java EE Example

Is an extremely lightweight efficient Java library to generate XHTML or XML in a micro DSL builder/fluent style.

A library that supports gettext-based internationalization (i18n) of Java applications.

Papaya: Utilities for Java 1.8+ written by Kevin Connor ARPE

charts4j is a free, lightweight charts and graphs Java API. It enables developers to programmatically create the charts available in the Google Chart API through a straightforward and intuitive Java API.

Fast and robust NLP components implemented in Java.

Java API for sending Passive Checks to Nagios NSCA addon

jCSV is a simple CSV library for Java

Very simple command-line shell for Java applications