tl;dr
In your project POM, change this:
<artifactId>vaadin</artifactId>
…to this, adding -core:
<artifactId>vaadin-core</artifactId>
Yes, open-source & free-of-cost
Yes, Vaadin is indeed an open-source project. Yes, you can build web apps free-of-cost.
- A panoply of high-quality widgets are bundled for you to use free-of-cost. This bundled collection of components may be all you need to build your web app. Browse this catalog of bundled widgets where the items without the yellow "Commercial" label are free-of-cost.
- In addition, there are hundreds of add-ons available, many free-of-cost, listed on the Vaadin Directory site.
- Casting a wider net, you can likely adapt most any Web Components based widget from third parties to work within Vaadin, if you so desire. Many such widgets are available free-of-cost. For more info, see the Creating Components section of the Vaadin manual.
Commercial products available, but not required
The Vaadin Ltd company sells some additional products with special functionality, as well as selling consulting and training services. Those commercial products are clearly labeled in the catalog mentioned above. For example, Vaadin comes bundled with free-of-cost widgets for single-line & multi-line text entry, while they sell commercially a rich text editor. This is called open core business model. With this business model Vaadin Ltd can sustain development and maintenance of the free open source offering. So it is win-win both for those who use free and commercial offering.
To avoid the commercial products
You can very easily configure your new Vaadin project to avoid any possible use of the commercial widgets. As your only take-away from this page, just remember the word "core". Search your project’s POM for that word core. You will find a comment saying:
<dependencies>
<dependency>
<groupId>com.vaadin</groupId>
<!-- Replace artifactId with vaadin-core to use only free components -->
<artifactId>vaadin</artifactId>
…
➥ Simply change that value on the artifactId element from vaadin to vaadin-core.
<dependencies>
<dependency>
<groupId>com.vaadin</groupId>
<!-- Replace artifactId with vaadin-core to use only free components -->
<artifactId>vaadin-core</artifactId>
…
I suggest doing a Maven clean and install. When you run your project, you should no longer see that pink message.
If you ever wish to try the commercial widgets, change that element back, removing the -core part, and follow the terms of their licensing.
