gistfile1.js

require.config({
    paths: {
        jQuery: "libs/jquery/jquery-1.7.2.min",
        Underscore: "libs/underscore/underscore-1.3.3.min",
        Backbone: "libs/backbone/backbone-0.9.2.min"
//        Mustache: "libs/mustache/mustache"
    },
    shim: {
        Underscore: {
            exports: '_'
        },
        Backbone: {
            deps: ['Underscore', 'jQuery'],
            exports: 'Backbone'
        }
    }
});

require([
        'Backbone'
    ], function(B) {
        console.log(B.VERSION);
    }
);