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.

Sisu is a modular JSR330-based container that supports classpath scanning, auto-binding, and dynamic auto-wiring. Sisu uses Google-Guice to perform dependency injection and provide the core JSR330 support, but removes the need to write explicit bindings in Guice modules. Integration with other containers via the Eclipse Extension Registry and the OSGi Service Registry is a goal of this project.

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.

Pax Exam creates OSGi bundles for testing purposes. It lets the user take control of the OSGi framework, the test framework (e.g. JUnit) and the system under test at the same time.

Guice is a lightweight dependency injection framework for Java 6 and above.

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.

Hdrhistogram creates histograms that support recording and analyzing sampled data value counts across a configurable integer value range with configurable value precision within the range. Value precision is expressed as the number of significant digits in the value recording, and provides control over value quantization behavior across the value range and the subsequent value resolution at any given level.

Java-jboss-interceptors-api-spec implements the Interceptors API. Interceptors are used to interpose on business method invocations and specific events.

This package provides a Java runtime environment for and Java development kit. It supports enhanced class redefinition (DCEVM), includes a number of improvements in font rendering, keyboards support, windowing/focus subsystems, HiDPI, accessibility, and performance, provides better desktop integration and bugfixes not yet present in OpenJDK.

Xbean-reflect provides very flexible ways to create objects and graphs of objects for dependency injection frameworks

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.

The Apache Commons CLI library provides an API for parsing command line options passed to programs. It is also able to print help messages detailing the options available for a command line tool.

Commons CLI supports different types of options:

• POSIX like options (ie. tar -zxvf foo.tar.gz)

• GNU like long options (ie. du --human-readable --max-depth=1)

• Java like properties (ie. java -Djava.awt.headless=true Foo)

• Short options with value attached (ie. gcc -O2 foo.c)

• long options with single hyphen (ie. ant -projecthelp)

This is a part of the Apache Commons Project.

JEXL is a library intended to facilitate the implementation of dynamic and scripting features in applications and frameworks written in Java. JEXL implements an Expression Language based on some extensions to the JSTL Expression Language supporting most of the constructs seen in shell-script or ECMAScript. Its goal is to expose scripting features usable by technical operatives or consultants working with enterprise platforms.

JOpt Simple is a Java library for parsing command line options, such as those you might pass to an invocation of javac. In the interest of striving for simplicity, as closely as possible JOpt Simple attempts to honor the command line option syntaxes of POSIX getopt and GNU getopt_long. It also aims to make option parser configuration and retrieval of options and their arguments simple and expressive, without being overly clever.

This package contains an HTTP/1.1 compliant HTTP agent implementation. It also provides reusable components for client-side authentication, HTTP state management, and HTTP connection management.

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

Guice is a lightweight dependency injection framework for Java 6 and above.

BeanShell is a small, free, embeddable Java source interpreter with object scripting language features, written in Java. BeanShell dynamically executes standard Java syntax and extends it with common scripting conveniences such as loose types, commands, and method closures like those in Perl and JavaScript.

This package provides the Java development kit OpenJDK.

QDox is a high speed, small footprint parser for extracting class/interface/method definitions from source files complete with JavaDoc @tags. It is designed to be used by active code generators or documentation tools.

Plexus-cipher contains a component to deal with encryption and decryption.

This package provides the Java development kit OpenJDK.

Plexus-cipher contains a component to deal with encryption and decryption.

Jansi is a Java library that allows you to use ANSI escape sequences to format your console output which works on every platform.