Bootstrap is the most popular HTML, CSS, and JS framework for developing responsive, mobile first projects on the web. This is used by the BootstrapSample skin. For some excellent free bootstrap templates for your projects head to http://www.bootstrapzero.com/.
geoPlugin is a free and easy webmaster resource to provide geolocation technology to your pages. Even though this is a core addon, it is only used by the YetaWF.VisitorsPackage (which is not enabled in a default installation). The geoPlugin.net service can also be used by any modules you add to YetaWF. This product includes GeoLite data created by MaxMind, available from http://www.maxmind.com.