Amiba is a Gene Expression Programming (GEP) framework for Java. GEP is, like genetic algorithms, a branch of evolutionary computing. The framework separates the process of evolution from the process of interpretation of the chromosome, allowing the use of various schemes. For example, graphs may be used as terminals and graph operations as operators in the chromosome instead of the usual double precision numbers. It implements mutation, transposition, and recombination. Options and rates are easily configured through an XML file. A mechanism to load fitness cases in bulk is also provided.
Ammentos is a lightweight persistence framework for JDK 5. It does not require any installation nor configuration; just put a jar file into your classpath and start writing code. It is designed so that your persistence code will be dramatically short and so that you won't have to spend a lot of time to learn how to use it. It is about 72Kb large and it does not require any external library except for your database JDBC driver. You can use it in desktop applications or in server-based environments.
Apache ActiveMQ is a popular and powerful message broker and enterprise integration patterns provider. Apache ActiveMQ is fast, supports many cross language clients and protocols, comes with easy-to-use enterprise integration patterns and many advanced features, while fully supporting JMS 1.1 and J2EE 1.4.
Apache Cayenne is a persistence framework that provides object-relational mapping (ORM) and remoting services. It has a wealth of unique and powerful features and can address a wide range of persistence needs. Cayenne seamlessly binds one or more database schemas directly to Java objects, managing atomic commit and rollbacks, SQL generation, joins, sequences, and more. With Cayenne's Remote Object Persistence, those Java objects can even be persisted out to clients via Web Services. With native XML serialization, objects can be even further persisted to non-Java clients.
With MetaModel, you use a type-safe SQL-like API for querying any datastore. It is a data access framework providing a common interface for exploration and querying of different types of datastores. It isn't a data mapping framework. Instead, it emphasizes abstraction of metadata and the ability to add data sources at runtime, making MetaModel great for generic data processing applications, but less so for applications modeled around a particular domain.
Apache XML Graphics Commons is a library that consists of several reusable components used by Apache Batik and Apache FOP. Many of these components can easily be used separately outside the domains of SVG and XSL-FO. You will find components such as a PDF library, an RTF library, Graphics2D implementations that let you generate PDF and PostScript files, and much more.
ApacheDS is an LDAP and X.500 experimentation platform. Its backend subsystem and frontend are separable and independently embeddable. It provides a server side JNDI LDAP provider that directly interacts with the backend storage. It is powered by SEDA (Staged Event-Driven Architecture), which can handle large amounts of concurrency.