Struts 最初是 Jakarta项目中的一个子项目，并在2004年3月成为ASF的顶级项目。它通过采用 Java Servlet/JSP 技术，实现了基于Java EE Web应用的MVC设计模式的应用框架，是MVC经典设计模式中的一个经典产品
Velocity是一个基于java的模板引擎（template engine）。它允许任何人仅仅简单的使用模板语言（template language）来引用由java代码定义的对象。
Apache Ignite is a horizontally scalable, fault-tolerant distributed in-memory computing platform for building real-time applications that can process terabytes of data with in-memory speed.
Jackrabbit Oak is a scalable, high-performance hierarchical content repository designed for use as the foundation of modern world-class web sites and other demanding content applications.
Apache ActiveMQ is a high performance Apache 2.0 licensed Message Broker and JMS 1.1 implementation.
Apache NiFi is an easy to use, powerful, and reliable system to process and distribute data.
Apache Beam is a unified model for defining both batch and streaming data-parallel processing pipelines, as well as a set of language-specific SDKs for constructing pipelines and Runners for executing them on distributed processing backends, including Apache Flink, Apache Spark, Google Cloud Dataflow and Hazelcast Jet.
Apache Camel 是一个非常强大的基于规则的路由以及媒介引擎，该引擎提供了一个基于POJO的 企业应用模式(Enterprise Integration Patterns)的实现，你可以采用其异常强大且十分易用的API (可以说是一种Java的领域定义语言 Domain Specific Language)来配置其路由或者中介的规则
