---
title: Overview
order: 1
layout: page
---

[[addons.overview]]
= Overview

In addition to the components, layouts, themes, and data sources built in into
the core Vaadin library, many others are available as add-ons.
link:http://vaadin.com/directory/[Vaadin Directory] provides a rich collection
of add-ons for Vaadin, and you may find others from independent sources. Add-ons
are also one way to share your own components between projects.

== Installing

Installing add-ons from Vaadin Directory is simple, just adding a Maven or an Ivy dependency, or downloading the JAR package and and dropping it in the web library folder of the project.

[[figure.addons.maven.widgetset]]
.Role of the widget set
image::img/addon-architecture.png[width=75%, scaledwidth=80%]

Most add-ons include _widgets_, client-side counterparts of the server-side components used in the Vaadin Java API, as illustrated in <<figure.addons.maven.widgetset>>.
The _widget set_ needs to be compiled into the application widget set.

Adding the dependency in Maven projects and compiling the widget set is described in <<addons-maven#addons.maven, "Using Add-ons in a Maven Project">>.
The section also describes how to use the online compilation and CDN services during development.

For Eclipse projects that use Ivy for dependency management, see <<addons-eclipse#addons.eclipse, "Installing Add-ons in Eclipse with Ivy">>.
You can also download and install add-ons from a ZIP-package, as described in <<addons-downloading#addons.downloading, "Downloading Add-ons from Vaadin Directory">>.

== Add-on Licenses

Add-ons available from Vaadin Directory are distributed under different
licenses, of which some are commercial. While the add-ons can be downloaded
directly, you should note their license and other terms and conditions. Many are
offered under a dual licensing agreement so that they can be used in open source
projects for free, and many have a trial period for closed-source development.
Commercial Vaadin add-ons distributed under the CVAL license require installing
a license key as instructed in
<<dummy/../../../framework/addons/addons-cval#addons.cval, "Installing Commercial Vaadin Add-on Licence">>.

== Feedback and Support

After trying out an add-on, you can give some feedback to the author of the
add-on by rating the add-on with one to five stars and optionally leaving a
comment. Most add-ons also have a discussion forum thread for user feedback and
questions.
