Edit in JSFiddle

<label>
    <input type="checkbox" value="webforms" data-bind="checked: techniques" />ASP.NET Web Forms
</label>
<label>
    <input type="checkbox" value="mvc" data-bind="checked: techniques" />ASP.NET MVC
</label>
<label>
    <input type="checkbox" value="webapi" data-bind="checked: techniques" />ASP.NET Web API
</label>
<div data-bind="text: techniques().join(', ')"></div>
function ViewModel() {
    var self = this;
    self.techniques = ko.observableArray();
}

ko.applyBindings(new ViewModel());