Apache Log4j 2 is a versatile, feature-rich, efficient logging API
Manifold is a Java compiler plugin, features include Metaprogramming
Source for the TechEmpower Framework Benchmarks project
Java dataframe and visualization library
Powerful generator for Java applications (JPA, Java EE...)
Evaluador de expresiones matemáticas para Java en español
Simple message-based, web-based ETL integration
A library for creating decision tables written in Java.
Lightweight fully extendable client/server application framework
Library tools to collect timing in Java, C, C++