The YUI 2in3 Project has been deprecated as of October 7, 2013.
You should not use YUI 2in3 for new projects, and we recommend you migrate to YUI 3.

YUI 2in3 Project

This project contains the all of the supported versions of YUI 2 wrapped
as first class YUI 3 modules, and deployed in a directory structure that
can be intrinsically loaded by YUI 3.1.0+.

Serving the 2in3 files from your local server

Copy all of the files in the dist directory to the location
you wish to serve the files from. Configure your YUI instance
to pull from that location:

YUI({
    groups: {
        yui2: {
            base: '/2in3/',

            // If you have a combo service, you can configure that as well
            // combine: true,
            // comboBase: 'http://myserver.com/combo?',
            // root: '/2in3/build/',

            patterns:  {
                'yui2-': {
                    configFn: function(me) {
                        if(/-skin|reset|fonts|grids|base/.test(me.name)) {
                            me.type = 'css';
                            me.path = me.path.replace(/\.js/, '.css');
                            me.path = me.path.replace(/\/yui2-skin/, '/assets/skins/sam/yui2-skin');
                        }
                    }
                }
            }
        }
    }
}).use('yui2-yahoo', 'yui2-event', function (Y) {
    //
};

Additional Notes

• YUI 3.3.0 will try to pull the 2.8.2 version of YUI 2 by default.
  The ‘yui2’ config can be passed to the instance to load one
  of the other versions.

• The files under src/script can be used to generate the 2in3 modules,
  but this is lightly documented and there are some path assumptions
  built in.