A Google Mapplet is an application that runs inside a Google Maps results page and lets you add your own custom information to the page and the map. In this tutorial, you will write a Google Mapplet that uses the Yahoo Weather RSS feed to display the local weather in Google Maps. You will apply two solutions. The first is on the client side and uses RSS and JavaScript. The second is on the server side and uses XSLT, PHP, KML, and JavaScript.