Canadian device manufacturer Research In Motion (RIM) on Tuesday showed off its BlackBerry Widget Software Development Kit (SDK) – a suite of tools allowing third party application developers to build rich, web-based applications for BlackBerry handsets.

The new offering bring RIM into line with the rest of the mobile OS world, whereas it previously only supported BlackBerry applications written in Java, a BlackBerry widget uses the handset’s browser engine to render an application’s user interface using HTML, CSS, and JavaScript.

Developers are then able to use existing web content to create BlackBerry Widgets and extend the capabilities of their web applications using optimised APIs, while interacting with the BlackBerry email and calendar applications, files and documents stored on the device, and location-based services or the media player.

Developers can also take advantage of RIM’s push technology, enabling dynamic widgets to run in the background and provide alerts and updates to users. The SDK runs on version 5.0 of the BlackBerry OS and a beta release of the BlackBerry Widget SDK is available today.

In related news, Palm announced plans to officially open the doors to its Palm webOS developer programme in December. The program will offer developers the opportunity to get their applications to market.

In August, Palm invited developers who wish to charge for their webOS applications to begin submitting them for consideration in the Palm App Catalog e-commerce beta program, which went live this week.

Developers will receive a 70/30 split (developer/Palm) of gross revenues generated from app sales, with a membership fee of $99 per year, which is waived for open source apps. As well as the online app store, developers can also have apps reviewed by Palm for inclusion in the Palm App Catalog that is built in to every Palm webOS.