There are so many terms floating around to call these little floating windows that developers are creatings for the desktop users. Not surprising, considering the fact that the terms are just beginning to gain currency, and it would be a while before the larger populace decides what to call this thingummajigs.
Newsweek called it widgets - though what they wrote about were desktop gadgets from Microsoft and Apple. Whats the difference? Not very much in the eyes of the users, maybe, but plenty in the eyes of the developer.
My take on these terms, and the difference between them:
1. Widgets: Small snippets of code-enabled-HTML that can be embedded in HTML pages by end-users themselves. The widget contains content that is hosted on some server, either owned by the end user or by some content provider - but the widget itself is displayed on some other site than the original hosted site. Typically on the "social" sites, such as Myspace, or on blogs, like this one. Widgets run on browsers only. Some people also call them web gadgets. Sigh - more names, more confusion
2. Gadgets/Desktop Gadgets: These are desktop applications that float a small pretty looking window on the users desktop. These are proper desktop applications that need to be installed on the desktop, in some cases, and do not need a browser. There are gadgets which work stand-alone, and are reasonably popular.
And then are some gadgets that require engines to run them. Typically, they have a mother application that provide the run-time environment for these pretty little windows. The mother application, called by some as the Widget Engine , has a interface that sits on the user desktop - as a sidebar, or as a toolbar. This mother application, or widget engine, hosts the pretty little windows, called Gadget (or desktop gadget) which runs within it. Google Desktop is one such example, and the MicrosoftVista gadgets are another. In case of the Google desktop, users have the download the Google Desktop on their machines. In case of Microsoft Vista, Vista comes bundled with the Vista Sidebar, and with some out-of-the-box gadgets. In both cases, other developers (other than Google and Microsoft) can build gadgets for the Sidebar, and make it available to end-users. Though the point looks obvious, but it still needs to be stated - Gadgets built for Vista would not run on other Gadget Siderbars, such as say, Google Desktop and vice versa.
There are people who call these desklets also. Yikes, another term...
3. Pagelets: These are again small code-enabled-HTML snippets that run on HTML pages, and need a browser to run. Much like widgets, but with a key difference. All the widgets, er, pagelets, are hosted on one Pagelet Server. Much like the "portals" of previous years, these pagelet server providers provide a entry page, where several widgets are hosted, each displaying its own content. Much like the previous portal pages, users can personalise their home pagelet page to suit their preferences. Needless to say, these too are available only through a browser. Best examples of these are Netvibes and fittingly called Pageflakes.
The underlying idea for all three, namely Widgets, Desktop Gadgets and pagelets is the same. To extend the idea of proving data within users' context, and go beyond providing links. All of them are designed to create a user experience that is connected, easy to use, and within the users context, a crying need for information crunchers today. They are also similar in another respect - that of getting data from mutliple places from the web, or some other data stores, and placing it within a particular context.
What the difference is, is really the context. In case of Widgets, the context is a page, owned and managed by the user. In desktop gadgets, the desktop of the user is the context, and in pagelets, the pagelet provider's portal page is the context. Does context matter?
I think it matters a great deal. But more on that later