MercurialEclipse is a plugin for the Eclipse platform to use the Mercurial source control system.

H2 is an SQL database engine written in Java. It is very fast and small (about 1 MB), and supports embedded, server, and clustering modes. A browser based console application is included. Disk based and in-memory tables and databases are supported.

Some of its features are transactions isolation, multi-version concurrency (MVCC), table level locking, encrypted databases, fulltext search, and strong security. ...

Red5 is an Open Source Flash Server written in Java that supports:

- Streaming Audio/Video (FLV and MP3)
- Recording Client Streams (FLV only)
- Shared Objects
- Live Stream Publishing
- Remoting

Rhino is an open-source implementation of JavaScript written entirely in Java. It is typically embedded into Java applications to provide scripting to end users.

Discover a clean alternative to bloated enterprises Java stacks. Play! focuses on developer productivity and targets RESTful architectures.

JiBX is a framework for binding XML data to Java objects. It lets you work with data from XML documents using your own class structures. The JiBX framework handles all the details of converting your data to and from XML based on your instructions. JiBX is designed to perform the translation between internal data structures and XML with very high efficiency, but still allows you a high degree of control over the translation process....

Alfresco offers true Open Source Enterprise Content Management (ECM) - Document Management, Collaboration, Records Management, Knowledge Management, Web Content Management and Imaging.

FreeMarker is a "template engine"; a generic tool to generate text output (anything from HTML to autogenerated source code) based on templates. It's a Java package, a class library for Java programmers. It's not an application for end-users in itself, but something that programmers can embed into their products....

L2J is a server application that emulates a Lineage II (a MMORPG) server. Players can play on a L2J server using the original Lineage II client. It was built from scratch in Java.

Apache CloudStack (Incubating) is an open source Cloud Computing platform used to deliver Infrastructure as a Service (IaaS). CloudStack enables users to build, manage and deploy compute cloud environments.

CloudStack forms the foundation for infrastructure clouds, data center operators can quickly and easily build cloud services within their existing infrastructure to offer on-demand, elastic cloud services. CloudStack users can take full advantage of cloud computing to deliver higher efficiency, limitless scale and faster deployment of new services and systems to the end-user. CloudStack will allow user to coordinate virtualized servers, networking and network storage to provide infrastructure-as-a-service (IaaS) just like hosting providers but on their own hardware....