The Java Collections Framework is the recognised standard for collection handling in Java. Commons-Collections seek to build upon the JDK classes by providing new interfaces, implementations and utilities. There are many features, including:

• Bag interface for collections that have a number of copies of each object

• BidiMap interface for maps that can be looked up from value to key as well and key to value

• MapIterator interface to provide simple and quick iteration over maps

• Transforming decorators that alter each object as it is added to the collection

• Composite collections that make multiple collections look like one

• Ordered maps and sets that retain the order elements are added in, including an LRU based map

• Reference map that allows keys and/or values to be garbage collected under close control

• Many comparator implementations

• Many iterator implementations

• Adapter classes from array and enumerations to collections

• Utilities to test or create typical set-theory properties of collections such as union, intersection, and closure.

Commons-dbcp allows you to share a pool of database connections between users. Creating a new connection for each user can be time consuming and even unfeasible when the number of simultaneous users is very large. This package provides a way to share a poole of connections to reduce that load.

ANTLR (ANother Tool for Language Recognition) is a powerful parser generator for reading, processing, executing, or translating structured text or binary files. It's widely used to build languages, tools, and frameworks. From a grammar, ANTLR generates a parser that can build and walk parse trees.

OpenJFX is a client application platform for desktop, mobile and embedded systems built on Java. Its goal is to produce a modern, efficient, and fully featured toolkit for developing rich client applications. This package contains UI control classes for the OpenJFX distribution.

Woodstox is a stax XML API implementation.

JLine is a Java library for handling console input. It is similar in functionality to BSD editline and GNU readline but with additional features that bring it in par with ZSH line editor. People familiar with the readline/editline capabilities for modern shells (such as bash and tcsh) will find most of the command editing features of JLine to be familiar.

This package includes the Terminal API and implementations.

XMLUnit provides you with the tools to verify the XML you emit is the one you want to create. It provides helpers to validate against an XML Schema, assert the values of XPath queries or compare XML documents against expected outcomes.

jakarta-regexp is an old regular expression parser generator for Java.

OpenJFX is a client application platform for desktop, mobile and embedded systems built on Java. Its goal is to produce a modern, efficient, and fully featured toolkit for developing rich client applications. This package contains graphics-related classes for the OpenJFX distribution.

Bnd is a swiss army knife for OSGi, it creates manifest headers based on analyzing the class code, it verifies the project settings, it manages project dependencies, gives diffs jars, and much more.

Jakarta Annotations defines a collection of annotations representing common semantic concepts that enable a declarative style of programming that applies across a variety of Java technologies.

This package provides the Eclipse content mechanism in the org.eclipse.core.contenttype module.

This package contains general purpose annotations for the Jackson Data Processor, used on value and handler types. The only annotations not included are ones that require dependency to the Databind package.

Sisu is a modular JSR330-based container that supports classpath scanning, auto-binding, and dynamic auto-wiring. This package adds Plexus support to the Sisu-Inject container.

Binding/provider for NOP, an implementation that silently discards all logging messages.

This package provides versions of the JavaMail API implementation, IMAP, SMTP, and POP3 service providers, some examples, and documentation for the JavaMail API.

This package provides various Java utility classes for the Plexus framework to ease working with strings, files, command lines, XML and more.

Mockito is a mocking library for Java which lets you write tests with a clean and simple API. It generates mocks using reflection, and it records all mock invocations, including methods arguments.

This package provides an extension to earlier versions of easymock that allows mocking classes.

This package provides the Eclipse core file system with the module org.eclipse.core.filesystem.

This package provides the Java development kit OpenJDK.

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 osgi-service-component.

This package specifies a means for obtaining objects in such a way as to maximize reusability, testability and maintainability compared to traditional approaches such as constructors, factories, and service locators (e.g., JNDI). This process, known as dependency injection, is beneficial to most nontrivial applications.

Many types depend on other types. For example, a Stopwatch might depend on a TimeSource. The types on which a type depends are known as its dependencies. The process of finding an instance of a dependency to use at run time is known as resolving the dependency. If no such instance can be found, the dependency is said to be unsatisfied, and the application is broken.

java-native-access-platform has cross-platform mappings and mappings for a number of commonly used platform functions, including a large number of Win32 mappings as well as a set of utility classes that simplify native access.