Echo is a

web application framework A web framework (WF) or web application framework (WAF) is a software framework that is designed to support the development of web applications including web services, web resources, and web APIs. Web frameworks provide a standard way to build and ...

created by the company NextApp. The latest iteration, Echo3, allows writing applications in either server-side

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mo ...

or client-side

JavaScript JavaScript (), often abbreviated as JS, is a programming language that is one of the core technologies of the World Wide Web, alongside HTML and CSS. As of 2022, 98% of Website, websites use JavaScript on the Client (computing), client side ...

. Server-side applications do not require developer knowledge of HTML, HTTP, or JavaScript. Client-side JavaScript-based applications do not require a server, but can communicate with one via

AJAX Ajax may refer to: Greek mythology and tragedy * Ajax the Great, a Greek mythological hero, son of King Telamon and Periboea * Ajax the Lesser, a Greek mythological hero, son of Oileus, the king of Locris * ''Ajax'' (play), by the ancient Gree ...

. It is

free software Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, ...

licensed under the terms of the

Mozilla Public License The Mozilla Public License (MPL) is a free and open-source weak copyleft license for most Mozilla Foundation software such as Firefox and Thunderbird The MPL license is developed and maintained by Mozilla, which seeks to balance the conce ...

(MPL).

Echo2

Echo originally started as a request-response web application framework that leveraged the

Swing Swing or swinging may refer to: Apparatus * Swing (seat), a hanging seat that swings back and forth * Pendulum, an object that swings * Russian swing, a swing-like circus apparatus * Sex swing, a type of harness for sexual intercourse * Swing rid ...

object model to improve the speed of application development. Through the use of the Swing model, Echo was able to employ concepts such as components and

event-driven programming In computer programming, event-driven programming is a programming paradigm in which the flow of the program is determined by events such as user actions (mouse clicks, key presses), sensor outputs, or message passing from other programs or th ...

that removed much of the pain of web application development. In late 2005, NextApp formally announced the release of their new

Ajax Ajax may refer to: Greek mythology and tragedy * Ajax the Great, a Greek mythological hero, son of King Telamon and Periboea * Ajax the Lesser, a Greek mythological hero, son of Oileus, the king of Locris * ''Ajax'' (play), by the ancient Gree ...

based web application platform, "Echo2". This framework built on the concepts of Echo (well known API, total web

abstraction Abstraction in its main sense is a conceptual process wherein general rules and concepts are derived from the usage and classification of specific examples, literal ("real" or " concrete") signifiers, first principles, or other methods. "An a ...

) but delivered the additional benefit of being an Ajax environment. NextApp believed that this approach brought the framework extremely close to the capabilities of rich clients. NextApp also claimed that this reincarnation of the Echo framework provided dramatic

performance A performance is an act of staging or presenting a play, concert, or other form of entertainment. It is also defined as the action or process of carrying out or accomplishing an action, task, or function. Management science In the work place ...

, capability, and user-experience enhancements made possible by its new Ajax-based rendering engine.

Echo3

During 2007, development on a third generation of the framework, Echo3, began. The focus of this evolution was to move away from generating markup on the server side, and instead to implement rendering peers as native

objects, with an

XML Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing arbitrary data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. ...

-based state synchronization protocol between client (web browser) and server. This was developed in tandem with a core JavaScript framework, providing the ability to define inheritance hierarchies in

in a way familiar to developers of

object-oriented Object-oriented programming (OOP) is a programming paradigm based on the concept of " objects", which can contain data and code. The data is in the form of fields (often known as attributes or ''properties''), and the code is in the form of ...

languages.

Competitors

Echo is often compared to frameworks such as

Google Web Toolkit Google Web Toolkit (GWT ), or GWT Web Toolkit, is an open-source set of tools that allows web developers to create and maintain JavaScript front-end applications in Java. It is licensed under the Apache License 2.0. GWT emphasizes reusable ...

(GWT) as both Echo and GWT (among others) offer a programming model that completely abstracts users from the web tier. However Echo differs substantially from GWT in the way it interacts with

. GWT essentially implements a subset of the

Java API There are two types of Java programming language application programming interfaces (APIs): * The official core Java API, contained in the Android (Google), SE (OpenJDK and Oracle), MicroEJ. These packages (java.* packages) are the core Java l ...

in JavaScript, and as such, Java code is compiled to JavaScript and fully executed on the client side. On the other hand, Echo has offered a dual-stack approach since version 3. Applications can be written in JavaScript (client-side) or Java (server-side) or in mixed forms. Comparable frameworks include Vaadin, RAP, ZK, OpenLaszlo, ICEfaces, ThinWire,

Apache Wicket Apache Wicket, commonly referred to as Wicket, is a component-based web application framework for the Java programming language conceptually similar to JavaServer Faces and Tapestry. It was originally written by Jonathan Locke in April 2004. Ver ...

, and jSeamless.

Associated projects

Echo2 has inspired various add-on projects including: * EchoPoint: "Next Generation": The most well known 3rd party component library for Echo2 * Hibernate-Spring-Echo: An effort to provide an out of the box application framework that includes Echo2 * Google maps for Echo2 * Google maps v3 for Echo2 * Gantt Charting for Echo2 * Echo2Faces: An effort to provide XML markup for Echo2 UI layouts * jZeno: A full-stack application framework that uses a highly optimized version of the original Echo framework as rendering engine. * Aejaks: A Jacl layer on top of Echo2 to easily create rich web applications.

References

External links