BlueJ is an interactive Java development environment. It provides a unique user interface that presents a graphical display of the application classes and their relationships, and it lets users interactively create objects of any class. Once objects have been created, users can interact with them directly. This interaction mechanism allows for much greater testing and experimentation than in conventional environments. BlueJ is suited for teaching and learning OO and Java.
db4o is an object database for Java and all .NET environments. Its features include ACID transactions, automatic class schema recognition, query-by-example, a S.O.D.A. object querying API, native queries, LINQ support on .NET, callback methods, memory files, cascade-on-delete, multi-threaded access, and Java Webstart and servlet support.
Jmol is a Free, Open Source molecule viewer and editor. It is a collaboratively developed visualization and measurement tool for chemical scientists. Jmol is an active project, and there are new features being added to it on a daily basis. Users are encouraged to modify it to fit their needs and to contribute their changes to the project.
JSX serializes Java objects to XML. You can persist objects, evolve them, and send them over the network and between applications. Your object data becomes human-readable and human-writable. You can test it, search it, profile it, audit it, and edit it with ordinary text and XML tools. JSX handles all POJOs and also all classes that require Java's own object serialization. JSX also correctly and completely handles the content of Serializable classes - including when they evolve and add additional content, for both upgrading to a new version (e.g. of Java or third-party libraries) and downgrading to an older one. It does this by reusing a class's Serialization methods, which are maintained by the class's developer to handle its evolution.
MUSCLE (Multi User Server Client Linking Environment) is an N-way messaging server and networking API. It includes client-side networking APIs for various languages, including C, C++, C#, Delphi, Java, and Python. MUSCLE lets programs communicate over a network via streams of serialized Message objects. The included server program ("muscled") lets its clients message each other and store information in its server-side hierarchical database. The database supports flexible queries via hierarchical wildcarding, and "live" updates via a subscription mechanism.
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.
OpenEJB is a simple, lightweight Enterprise JavaBeans (EJB) container and server. You can embed OpenEJB in your own applications, or in a Web application server like Tomcat, or run it as a standalone EJB server. It supports EJB 3.0, 2.1, 2.0, and 1.1, and has partial support for EJB 3.1.
Ptplot is a set of Java classes that can be used as an applet or an application for graphing datasets. It reads PlotML, binary, or ASCII data, is autoranging, and automatically or manually labels axes and tick marks. It can plot live, animated plots and provides zooming. It also includes Bourne shell scripts and DOS .bat files that can be used as a replacement for xgraph, the X11 graphing tool.