LIBANTLR3C provides run-time C libraries for ANTLR3 (ANother Tool for Language Recognition v3).

ASM is an all purpose Java bytecode manipulation and analysis framework. It can be used to modify existing classes or dynamically generate classes, directly in binary form. The provided common transformations and analysis algorithms allow easily assembling custom complex transformations and code analysis tools.

OPS4J stands for Open Participation Software for Java. This package contains utilities and extensions related to handling streams and files.

BeanUtils provides a simplified interface to reflection and introspection to set or get dynamically determined properties through their setter and getter method.

Java Servlet is the foundation web specification in the Java Enterprise Platform. Developers can build web applications using the Servlet API to interact with the request/response workflow. This project provides information on the continued development of the Java Servlet specification.

Guava is a set of core libraries that includes new collection types (such as multimap and multiset), immutable collections, a graph library, functional types, an in-memory cache, and APIs/utilities for concurrency, I/O, hashing, primitives, reflection, string processing, and much more!

ASM is an all purpose Java bytecode manipulation and analysis framework. It can be used to modify existing classes or dynamically generate classes, directly in binary form. The provided common transformations and analysis algorithms allow easily assembling custom complex transformations and code analysis tools.

ANTLR, ANother Tool for Language Recognition, (formerly PCCTS) is a language tool that provides a framework for constructing recognizers, compilers, and translators from grammatical descriptions containing Java, C#, C++, or Python actions. ANTLR provides excellent support for tree construction, tree walking, and translation.

This package provides a library of matcher objects (also known as constraints or predicates) allowing match rules to be defined declaratively, to be used in other frameworks. Typical scenarios include testing frameworks, mocking libraries and UI validation rules.

The Byte Code Engineering Library (Apache Commons BCEL) is intended to give users a convenient way to analyze, create, and manipulate (binary) Java class files. Classes are represented by objects which contain all the symbolic information of the given class: methods, fields and byte code instructions, in particular.

Such objects can be read from an existing file, be transformed by a program (e.g. a class loader at run-time) and written to a file again. An even more interesting application is the creation of classes from scratch at run-time. The Byte Code Engineering Library (BCEL) may be also useful if you want to learn about the Java Virtual Machine (JVM) and the format of Java .class files.

Picocli is a framework for building command line applications for the JVM. It supports colors, autocompletion, subcommands, and more. Written in Java, usable from Groovy, Kotlin, Scala, etc.

OSGi, for Open Services Gateway initiative framework, is a module system and service platform for the Java programming language. This package contains the OSGi org.osgi.service.event module.

OSGi, for Open Services Gateway initiative framework, is a module system and service platform for the Java programming language. This package contains the support annotations for metatype.

This package provides the Eclipse jobs mechanism.

The Apache Commons Compress library defines an API for working with compressed files such as ar, cpio, Unix dump, tar, zip, gzip, XZ, Pack200, bzip2, 7z, arj, lzma, snappy, DEFLATE, lz4 and Z files.

StringTemplate is a java template engine (with ports for C#, Objective-C, JavaScript, Scala) for generating source code, web pages, emails, or any other formatted text output. StringTemplate is particularly good at code generators, multiple site skins, and internationalization / localization. StringTemplate also powers ANTLR.

The JUnitParams project adds a new runner to JUnit and provides much easier and readable parametrised tests for JUnit.

SnakeYAML is a YAML processor for the Java Virtual Machine.

Tinybundles is all about creating OSGi related artifacts like Bundles, Fragments and Deployment Packages with Java Api. It is very convenient to create such artifacts on-the-fly inside Tests (like in Pax Exam). On the other hand, this library can be a foundation of real end user tools that need to create those artifacts.

Conversant Disruptor is the highest performing intra-thread transfer mechanism available in Java. Conversant Disruptor is an implementation of this type of ring buffer that has almost no overhead and that exploits a particularly simple design.

Argparse4j is a command line argument parser library for Java based on Python's argparse module.

This is a word-aligned compressed variant of the Java Bitset class. It provides both a 64-bit and a 32-bit RLE-like compression scheme. It can be used to implement bitmap indexes.

The goal of word-aligned compression is not to achieve the best compression, but rather to improve query processing time. Hence, JavaEWAH tries to save CPU cycles, maybe at the expense of storage. However, the EWAH scheme is always more efficient storage-wise than an uncompressed bitmap (as implemented in the BitSet class by Sun).

JGit is a lightweight, pure Java library implementing the Git version control system, providing repository access routines, support for network protocols, and core version control algorithms.

Error Prone is a static analysis tool for Java that catches common programming mistakes at compile-time. This package contains annotations used by programmers to guide the static analysis.