Type of Google Gadgets

Google Gadgets are mini-applications that work with the Google homepage, Google Desktop, or any page on the web. They can range from simple HTML to complex applications, and can be a calendar, a weather globe, a media player, or anything else you can dream up.

There are two types of Google Gadgets, Universal Gadget and Desktop Gadget.

Universal Gadget
Universal Gadget is works with Google homepage, Google Desktop or any page on the web.


Why create a universal gadget?

• works on webpages where you own the HTML source code, and on multiple Google properties (Personalized Homepage, Google Desktop, Google Page Creator, Blogger)
• easy to create - no downloads necessary, no libraries to learn, and no webserver required
  
• written in HTML and/or JavaScript

Why not create a universal gadget?

• subject to limitations of the browser environment
• does not work when the user is offline

Desktop Gadget
Desktop Gadget is only works with Google Desktop

Why create a desktop gadget?

• runs on the user's desktop, does not require a web browser to be open
• supports advanced functionality (offline access, client libraries, multi-user support through Google Talk, and free-form shapes)
• written in JavaScript, C, C++, C#, and/or VB.Net

Why not create a desktop gadget?

• only works with Google Desktop
• download required

Functionality details:
	Universal Gadgets	Desktop Gadgets
Work in	Google Personalized Homepage, Google Desktop, Google Page Creator, and your own webpage	Google Desktop
Computer languages supported	HTML, JavaScript, generated HTML (e.g. PHP, Perl, Java, ASP)	JavaScript, C, C++, C#, and/or VB.Net
Features supported	Anything you can do on a webpage HTML forms Easy integration with Google Maps and Google Web Search ActiveX Supported anywhere Google supports gadgets	Client libraries (i.e. Win32 libraries) Multi-user support through Google Talk (i.e. interactive games, shared lists, etc.) Free-form shapes and transparency (i.e. orb shaped weather globe) Find desktop files, emails, web history, and more with the Google Desktop query API Easy to use standard UI elements (i.e. details view, expanded view, alerts, etc.) React to user actions outside the gadget (i.e. user opens iTunes, user starts reading an email, etc.)
Create gadgets without a download	Yes	No
Works when the user is offline	No	Yes

Source: Google.com