Widgets are small applications that use information from the web or from your computer. Many software companies create widget frameworks these days: Yahoo acquired Konfabulator, Google has Google Desktop, Opera will have gadgets in Opera 9, Microsoft will include them in Windows Vista Sidebar, while Apple has an application for Mac OS X 10.4 called Dashboard. Let's see how each company presents its widgets (Google and Microsoft call them gadgets).

The Yahoo! Widget Engine is an application that allows light-weight files called "Widgets" to live directly on a user's desktop and perform a wide variety of tasks, such as checking for wi-fi presence or strength, finding contacts in an address book, viewing a user's calendar, or checking their latest e-mail. Widgets are built on an open platform, which allows any third party developer to build and distribute their own widgets.

Opera Widgets are small web applications run directly on a user’s desktop. With Opera Widgets you can quickly write small, focused applications that perform useful tasks. They can interact with online services such as news feeds, dictionaries or search engines.

Dashboard is a new world of beautiful accessory applications called widgets that appear instantly to give users immediate access to information like stock quotes, weather forecasts, airline flight tracking, unit of measure, currency conversions and a phone book. With a single click a user’s favorite Dashboard widgets instantly appear with up to the second information; with another click they’re instantly gone and the user is right back to where they left off.  Tiger ships with 14 widgets, and because Dashboard is based on standard web technologies such as HTML and JavaScript, it’s easy for third party developers to create new widgets that users can easily add to their Dashboards.

Also announced today, Google Desktop 4 beta – available in English, French, Italian, German, Spanish, Dutch, and Brazilian Portuguese – offers another way for users to improve their search experience, by personalizing their desktops with the introduction of Google Gadgets. These gadgets are mini-applications that reside on users' desktops and deliver a variety of personalized information such as games, media players, weather and news. Google Desktop can also recommend new gadgets and can automatically create a personalized homepage for users based on the subjects they frequently search and access.

Google currently has hundreds of gadgets users can add to their desktops and with the new Google Desktop Gadgets API, developers can easily create and share their own gadgets with other users.

Have you ever wondered how new technologies get developed in Microsoft? Wonder how a cool idea goes from incubation to release? Well, we’re excited to announce that we’ve started a blog designed to bring you closer to the process with the Gadgets blog and we’re kicking it off at the PDC.

What are Gadgets? Gadgets are a new category of mini-application designed to provide information, useful lookup, or enhance an application or service on your Windows PC or the Web. Examples might include a weather gadget running on your desktop or on your homepage, an RSS Gadget that pulls in your favorite feeds, or an extension of a business application providing just-in-time status on the pulse of your business.

Gadgets come in three flavors:

• Gadgets for Windows Sidebar will run on your desktop or dock into Windows Sidebar, an upcoming feature in Windows Vista alongside other applications. Desktop Gadgets can developed using Windows Presentation Foundation, DHTML/Atlas, and even ActiveX controls. The beauty of Desktop Gadgets is that they are visually and programmatically rich – scaling from vector-based graphics and managed code to standard techniques you’d use for the Web. You’ll be hearing more about Windows Sidebar over the coming months here as we approach release around Beta 2 of Windows Vista.
• Gadgets for Start.com (a.k.a. Web or Server-based Gadgets) provide a fast, customizable homepage with a clean user interface – putting the user in control of more of their online experience. Currently in incubation/public preview, Start.com is a place where consumers can customize the web to their liking by adding their own sources of content including RSS web-feeds and web-based Gadgets that extend functionality of their site- anything from custom calendars to service integration. Start.com demonstrates the use of DHTML and ASP.Net Atlas, which separates the data from the UI resulting in significant performance improvements. In addition, Start.com Gadgets can easily support docking into the Windows Sidebar.
• Gadgets for Windows SideShow(tm) (a.k.a. Auxilary Display Gadgets) allow users to view their information on devices. Users can view their data where they want it, whether it is for instant access on the lid of a laptop PC, for notifications on a keyboard display or for convenience on a detached device like a cell phone. Gadgets for Windows SideShow run on the PC and use COM interfaces to send data to devices. This Windows SideShow platform combined with the power of desktop applications allows for new scenarios and opportunities.

Yahoo! Widgets running under Windows XP with 'Heads Up' enabled.

Opera 9, the new version of the most underrated browser, brings a fresh look and more goodies than anyone would expect.

Dashboard widgets running under Mac OS X Tiger.