If you are looking to create some quick Mashup’s then you can try Google Mashup Editor. The Google Mashup Editor consists of a set of tools which will enable you to create AJAX-based applications. You can get the data from external RSS and Atom feeds as well as Google Base and Google maps. You can easily create mashups with Google Mashup Editor by using XML tags, JavaScript, CSS and HTML.

The good thing about Google Mashup Editor is that you can create, debug and deploy your application in one interface. The editor also includes a built-in reference guide to all GME tags and attributes. GME provides versatile modules through declarative XML tags and when it is used in conjunction with JavaScript, CSS and HTML, these tags allow you to create web applications and mashups quickly and easily. You can test the application easily and once you are happy you can publish it. You can even deploy your web application as a Google Gadget. The other good thing is that Google takes care of the storage, hosting and serving of your web application.

Recently Google had closed the Mashup Editor beta and focusing on the App Engine.