Just some namespace

namespace.js

(function() {

    function myNS() {

        var myNS = this;

        function _copy(target, source) {
            var key;
            for (key in source) {
                if (typeof target[key] === 'undefined') {
                    target[key] = source[key];
                } else {
                    myNS.log('ns already taken');
                }
            }
            return target;
        }

        function _create(name) {
            var node = window.myNS,
                parts = name ? name.split('.') : [],
                pl = parts.length,
                i;

            for (i = 0; i < pl; i++) {
                var part = parts[i];
                var nso = node[part];

                if (!nso) {
                    nso = {};
                    node[part] = nso;
                }
                node = nso;
            }
            return node;
        }

        this.log = function(string) {
            if(window.console) {
                window.console.log(string);
            }
        };

        this.extend = function(target, source) {
            return _copy(
                _create(target),
                source
            );
        }
    }

    window.myNS = window.myNS || new myNS();

})();

(function() {
    myNS.extend('tools', {
        tooloptions: function() {
            console.log('tooloptions');
        },

        tooloptions2: function() {
            console.log('tooloptions2');
        }
    });

    myNS.extend('tools.subtools', {
        subtooloptions: function() {
            console.log('subtooloptions');
        },

        subtooloptions2: function() {
            console.log('subtooloptions2');
        }
    });

    myNS.extend('othertools.subtools', {
        othersubtooloptions: function() {
            console.log('othersubtooloptions');
        },

        othersubtooloptions2: function() {
            console.log('othersubtooloptions2');
        }
    });

    myNS.extend('othertools.subtools', {
        othersubtooloptions: function() {
            console.log('overwrite here');
        },

        othersubtooloptions2: function() {
            console.log('overwrite here');
        }
    });

    console.log(myNS);
})();