Apache SpamAssassin is an extensible email filter that is used to identify spam. Once identified, the mail can then be optionally tagged as spam for later filtering. It provides a command line tool to perform filtering, a client-server system to filter large volumes of mail, and Mail::SpamAssassin, a set of Perl modules allowing Apache SpamAssassin to be used in a wide variety of email systems.
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.
The Apache Open For Business Project is an enterprise automation software project that includes ERP, CRM, E-Business/E-Commerce, SCM, MRP, and CMMS/EAM functions. It is a foundation and starting point for enterprise solutions and can certainly be used out of the box, but is also great for creating specialized applications.
Sculptor is a productivity tool that applies the concepts from Domain-Driven Design and Domain Specific Languages. You express your design intent in a textual specification, from which Sculptor generates high quality Java code and configuration. You can use the concepts from Domain-Driven Design (DDD) in the textual Domain Specific Language (DSL), e.g. Service, Module, Entity, Value Object, Repository. The generated code is based on well-known frameworks such as Spring Framework, Hibernate, and Java EE. Sculptor takes care of the technical details and the tedious repetitive work, and lets you focus on delivering more business value (and have more fun). The DSL and the code generation drives the development and is not a one time shot. The application can be developed incrementally with an efficient round trip loop. Sculptor is useful when developing typical enterprise or Web applications that benefit from a rich and persistent domain model.
Redland is a set of C libraries providing a high-level API for the Resource Description Framework (RDF), allowing it to be stored, parsed, serialized, queried, and manipulated. It has an object-based, modular design and comes with detailed reference documentation and examples. Redland supports all RDF vocabularies such as FOAF, RSS 1.0, Dublin Core, DOAP, and OWL, the query languages SPARQL and RDQL, and all RDF syntaxes including Turtle, RDF/XML, RDF/JSON, RSS, Atom, RDFa, and GRDDL.
WidgetServer is a Java/XML server-side GUI-framework which enables an application to run as either a monolithic Swing app, a client/server Swing app, or as a Web app without any change and without loss of functionality. An Eclipse Plugin is available as well. A rich widget set is supported that includes tree views, tabbed panes, split panels, and much more. Animations, all types of events, and several effects are supported, as well. A unified widget-based, object-oriented programming interface for Web and Swing GUIs is offered to the developer to control and assemble the GUI. Web applications are fully AJAX enabled. For Swing client/server applications, the framework handles client/server communication, including compression and security layers.
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.