Spring Beans provides the configuration framework and basic functionality to instantiate, configure, and assemble java objects.

Apache CXF Runtime JAX-WS Frontend

JMS support package, including helper classes to send/receive JMS messages

Spring Messaging provides abstractions such as Message, MessageChannel, MessageHandler, and others to serve as a foundation for messaging-based applications. It also includes a set of annotations for mapping messages to methods.

Spring Aspects integrates Spring with AspectJ.

Spring Data module for JPA repositories.

MongoDB support for Spring Data

Non-blocking web stack with support for 'Reactive Streams' back pressure, running on Netty, Undertow, and Servlet 3.1+ conts

A common REST support module used in Atlassian plugin development.

Confluence Core

Camel Spring