Spring Object/Relational Mapping which provides integration layers for popular object-relational mapping APIs, including JPA, JDO, and Hibernate.

Powerful Expression Language for querying and manipulating an object graph at runtime. It is an extension of the unified expression language (unified EL) as specified in the JSP 2.1 specification

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 Framework

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

Spring Commons Logging Bridge

Abstraction layer that supports Object/XML mapping implementations such as JAXB, Castor, XMLBeans, JiBX and XStream.

WebSocket and SockJS infrastructure, including STOMP messaging support.