原版：
Attributes
Runtime API to metadata attributes such as doclet tags.
BCEL
Byte Code Engineering Library - analyze, create, and manipulate Java class files
BeanUtils
Easy-to-use wrappers around the Java reflection and introspection APIs.
Betwixt
Services for mapping JavaBeans to XML documents, and vice versa.
BSF
Bean Scripting Framework - interface to scripting languages, including JSR-223
Chain
Chain of Responsibility pattern implemention.
CLI
Command Line arguments parser.
Codec
General encoding/decoding algorithms (for example phonetic, base64, URL).
Collections
Extends or augments the Java Collections Framework.
Compress
Defines an API for working with tar, zip and bzip2 files.
Configuration
Reading of configuration/preferences files in various formats.
CSV
Component for reading and writing comma separated value files.
Daemon
Alternative invocation mechanism for unix-daemon-like java code.
DBCP
Database connection pooling services.
DbUtils
JDBC helper library.
Digester
XML-to-Java-object mapping utility.
Discovery
Tools for locating resources by mapping service/reference names to resource names.
EL
Interpreter for the Expression Language defined by the JSP 2.0 specification.
Library for sending e-mail from Java.
Exec
API for dealing with external process execution and environment management in Java.
FileUpload
File upload capability for your servlets and web applications.
Functor
A functor is a function that can be manipulated as an object, or an object representing a single, generic function.
Imaging (previously called Sanselan)
A pure-Java p_w_picpath library.
IO
Collection of I/O utilities.
JCI
Java Compiler Interface
JCS
Java Caching System
Jelly
XML based scripting and processing engine.
Jexl
Expression language which extends the Expression Language of the JSTL.
JXPath
Utilities for manipulating Java Beans using the XPath syntax.
Lang
Provides extra functionality for classes in java.lang.
Launcher
Cross platform Java application launcher.
Logging
Wrapper around a variety of logging API implementations.
Math
Lightweight, self-contained mathematics and statistics components.
Modeler
Mechanisms to create Model MBeans compatible with JMX specification.
Net
Collection of network utilities and protocol implementations.
OGNL
An Object-Graph Navigation Language
Pool
Generic object pooling component.
Primitives
Smaller, faster and easier to work with types supporting Java primitive types.
Proxy
Library for creating dynamic proxies.
Sanselan (now called Imaging)
A pure-Java p_w_picpath library.
SCXML
An implementation of the State Chart XML specification aimed at creating and maintaining a Java SCXML engine. It is capable of executing a state machine defined using a SCXML document, and abstracts out the environment interfaces.
Transaction
Implementations for multi level locks, transactional collections and transactional file access.
Validator
Framework to define validators and validation rules in an xml file.
VFS
Virtual File System component for treating files, FTP, SMB, ZIP and such like as a single logical file system.