* RAP lets you develop modern web UIs with a real widget toolkit with SWT API, which includes powerful features like drag & drop, loading data on demand, inline editing, and drawing. * RAP runs in all relevant web browsers, without any add-ons required. Many advanced features like gradients are rendered even in browsers without CSS3 support. * RAP uses standard servlet technology and runs on any JEE servlet container. It integrates well with OSGi, but can also be used stand-alone. * RAP applications are written in Java, and you have the full power of Eclipse's development tools at hand. * With RAP, you can re-use your code for different target platforms. Even code that has been written for Eclipse RCP can run in a web browser.

* One language for the whole application - Java, the #1 programming language in the world, is probably already used by your persistency and business layer. With Vaadin, you'll leverage the same proven language, professional tooling and skills to build your web UI. No need to touch markup languages or JavaScript. * UI logic is right next to your data - Vaadin UI code lives in a JVM, in your web server. That's where your data and business logic also exist. This makes accessing your data and business logic really simple and efficient. No need to expose REST services or think up other ways to move the data to the browser. * Extensible with Java and HTML5 - The component-based programming model and Java encourage writing reusable modules. It is also easy to wrap existing HTML widgets or get down to the low level browser technologies when you need something special. There are also hundreds of community contributed extensions available. * Strong abstraction of web technologies - Familiar component-based programming model helps you to build modern single-page HTML5 apps, without getting your hands dirty with low level web technologies. You can apply the skills you have learned with UI frameworks, like Swing and SWT, and concentrate on your domain problems. Vaadin will take care of client-server communication, browser differences, markup languages, CSS and even upcoming new web technologies.