Ringo

Ringo is a CommonJS-based JavaScript runtime written in Java and based on the Mozilla Rhino JavaScript engine.

Download the final Ringo 0.8 release!

Our primary goal is to build a stable, high-performance runtime for server-side use. The following code is all you need to create a simple web app:

exports.app = function(req) {
    return {
        status: 200,
        headers: {"Content-Type": "text/plain"},
        body: ["Hello World!"]
    };
};

if (require.main == module)
    require("ringo/httpserver").main(module.id);

Simply save the code above as "server.js" and run it by executing ringo server.js. Like most Ringo apps, this app will automatically reload, picking up any changes you make without requiring a restart.

But Ringo lets you do more than write web applications. It allows you to seamlessly use any Java class or library simply by dropping it into the classpath. The following code shows how to build a simple desktop application with Swing:

var {JFrame, JButton} = javax.swing;

function main() {
    var frame = new JFrame("Hello World!");
    var button = new JButton("Bye bye");
    button.addActionListener(function(e) {
        system.exit();
    });
    frame.add("Center", button);
    frame.setSize(300, 300);
    frame.setVisible(true);
}

if (require.main == module)
    main();

See the Wiki or documentation page to learn more about Ringo!