Microsoft Gadgets
Microsoft Gadgets are lightweight single-purpose applications, or software widgets, that can sit on a Microsoft Windows user's computer desktop, or are hosted on a web page. According to Microsoft, it will be possible for the different types of gadgets to run on different environments without modification, but this is currently not the case.
Types of Microsoft's gadgets
Web gadgets - run on a web site, such as Bing.com or Spaces.
Sidebar gadgets - run on the desktop or be docked onto, run on the Windows Sidebar.
SideShow gadgets - run on auxiliary external displays, such as on the outside of a laptop or even on an LCD panel in a keyboard, and potentially mobile phones and other devices.
Web gadgets and Live.com
Web gadgets run on Web sites such as Live.com and Windows Live Spaces
Live.com lets users add RSS feeds in order to view news at a glance. Building off Microsoft's start.com experimental page, Live.com can be customized with Web Gadgets, mini-applications that can serve almost any purpose (e.g. mail readers, weather reports, slide shows, search, games, etc.). Some gadgets integrate with other Windows Live services, including Mail, Search, and Favorites.