The latest entry into the mobile-framework field is Sencha Touch, brought to you by the same people that created Ext JS, jQTouch and Raphael,

all of which have been combined under the name Sencha.

Sencha Touch, released this week, bills itself as “the first HTML5 framework for mobile devices,” which isn’t quite true. Several other mobile frameworks make use of HTML5 APIs like offline storage, or companion APIs like geolocation. But Sencha is nevertheless well worth a look if you’re thinking of building a cross-platform mobile app.

Sencha offers built-in support for the geolocation API and the offline storage API, and takes advantage of CSS 3 for smaller, image-less design elements. Because all the major mobile platforms — iOS, Android and WebOS — use similar WebKit-based browsers, there’s little to worry about when it comes to support for cutting edge features like HTML5 and CSS 3. Even when Firefox arrives on mobiles, you should expect support to be on par.

Sencha has some demos available if you’d like to see what’s possible. The GeoCongress demo makes use of the geolocation API to find out where you are and then show a list of your senators and representative. There’s also a very slick Solitaire demo that shows how to preserve an app’s state using the HTML5 local storage API.

The Sencha Touch code is available under a GPLv3 license. If you’d like to experiment with the code, head over to the new Sencha Touch site and grab a copy.

Sencha Touch Introduction from Sencha on Vimeo.