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.
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.
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.
fastutil extends the Java Collections Framework by providing type-specific maps, sets, lists, and queues for Java with a small memory footprint and fast access and insertion. It also provides big (64-bit) arrays, sets and lists, and fast, practical I/O classes for binary and text files.
Raptor is a C library providing a set of parsers and serializers for Resource Description Framework (RDF) triples by parsing syntaxes into RDF triples and serializing triples into a syntax. The parsers support RDF/XML, N-Triples, GRDDL, and Turtle, and via RSS tag soup: XML RSS, Atom 0.3, and Atom 1.0. The serializers support RDF/XML (3 flavours), Turtle, DOT, N-Triples, RSS 1.0, and Atom 1.0. Raptor handles RDF/XML as used by RDF applications such as RSS 1.0, FOAF, DOAP, Dublin Core, and OWL. It can use either expat or libxml2 for XML parsing, libcurl when available for URI retrieval, and is portable to many POSIX systems.
The Netty project is an effort to provide an asynchronous, event-driven network application framework and tools for rapid development of maintainable, high-performance, high-scalability protocol servers and clients. In other words, Netty is a NIO client server framework that enables quick and easy development of network applications such as protocol servers and clients. It simplifies and streamlines network programming such as TCP and UDP socket servers.
Spring IDE for Eclipse provides plugins for the Eclipse platform to ease working with Bean Factory configuration files for the Spring Framework. It contains a Spring project nature (with an incremental builder for validating Spring bean config files), an image decorator (which decorates Spring projects and all Spring bean config files), a Spring view (which allows one to browse Spring projects and their Spring bean config files, including bean properties), and an editor showing a graph from the beans of a single config file or a set of config files.
JCPP is a complete, compliant, standalone, pure Java implementation of the C preprocessor. It is intended to be of use to people writing C-style compilers in Java using tools like sablecc, antlr, JLex, CUP, and so forth. It has been used to successfully preprocess much of the source code of the GNU C library.