Example of publish and subscribe in Durandal. From Durandal's HTML Samples download.

index.html

<section>
    <div class="col-md-6" data-bind="compose: publisher"></div>
    <div class="col-md-6" data-bind="compose: subscriber"></div>
</section>

index.js

define(['./publisher', './subscriber'], function (publisher, subscriber) {
    return {
        publisher:publisher,
        subscriber: subscriber
    };
});

publisher.html

<div>
    <h1>Publisher</h1>
    <form class="form-inline" role="form">
        <div class="form-group">
            <input type="text" class="form-control" placeholder="message" data-bind="value: message, valueUpdate: 'afterkeydown'">
        </div>
        <button type="submit" class="btn btn-default" data-bind="click: publish, enable: canPublish">Publish</button>
    </form>
</div>

publisher.js

define(['durandal/app', 'knockout'], function (app, ko) {
    var message = ko.observable();
    var canPublish = ko.computed(function () {
        return message() ? true : false;
    });
 
    return {
        message: message,
        canPublish:canPublish,
        publish: function () {
            app.trigger('sample:event', message());
        }
    };
});

subscriber.html

<div>
    <h1>
        Subscriber
        <button class="btn btn-success" data-bind="enable: !subscription(), click: subscribe">Subscribe</button>
        <button class="btn btn-danger" data-bind="enable: subscription, click: unsubscribe">Unsubscribe</button>
    </h1>
    <ul data-bind="foreach: received">
        <li data-bind="text: $data"></li>
    </ul>
</div>

subscriber.js

define(['durandal/app', 'knockout'], function (app, ko) {
    return {
        received: ko.observableArray([]),
        subscription:ko.observable(),
        subscribe: function () {
            var sub = app.on('sample:event').then(function(message) {
                this.received.push(message);
            }, this);
 
            this.subscription(sub);
        },
        unsubscribe: function () {
            this.subscription().off();
            this.subscription(null);
        }
    };
});