A common issue when receiving data either electronically or from user input is verifying the integrity of the data. This work is repetitive and becomes even more complicated when different sets of validation rules need to be applied to the same set of data based on locale. Error messages may also vary by locale. This package addresses some of these issues to speed development and maintenance of validation rules....

A complete, Java-based solution for accessing, manipulating, and outputting XML data from Java code.

args4j is a small Java class library that makes it easy to parse command line options/arguments in your CUI application.

Protocol Buffers are a way of encoding structured data in an efficient yet extensible format. Google uses Protocol Buffers for almost all of its internal RPC protocols and file formats.

Open-Xchange sets the standard for email, messaging and collaboration in the cloud, with all the advantages of open data. It’s very easy to implement and support, and scales better than anything else on the market.

Integrates with your existing backend processes: billing, provisioning, databases and mail servers. It fits most complex heterogeneous environments without having to remove components, such as email servers. Lets you use your tools for authentication, user setup, system administration, procurement, accounting and email storage. ...

OpenNMS is the world's first enterprise grade network management platform developed under the open source model. It consists of a community supported open-source project as well as a commercial services, training and support organization.

Nuxeo provides an Open Source Content Management Platform enabling architects and developers to easily build, deploy, and run content-centric business applications. Its component-based and service-oriented architecture makes it easy to customize and extend, making developers more efficient and ultimately, happier!...

Griffon is an application framework for developing desktop applications in the JVM, with Groovy being the primary language of choice. Inspired by Grails, Griffon follows the Convention over Configuration paradigm, paired with an intuitive MVC architecture and a command line interface. Griffon also follows the spirit of the Swing Application Framework (JSR 296), it defines a simple yet powerful application life cycle and event publishing mechanism....

The DataNucleus project provides products for the management of application data in a Java environment. Our aim is to provide good quality open source products to handle data in all of its forms, wherever it is stored. This goes from persistence of data into heterogeneous datastores, to providing methods of retrieval using a range of query languages, and eventually on to the analysis of data and tools for managing data quality. ...

Neo4j is a graph database. It is an embedded, disk-based, fully transactional Java persistence engine that stores data structured in graphs rather than in tables. A graph (mathematical lingo for a network) is a flexible data structure that allows a more agile and rapid style of development....