Every once in a while it is good to remind clients that there is no "one size fits them all" widget. In fact, not only are there different general widget platforms, but each platform has its own widget types and technologies. There are generally four common types of widget platforms. Two established and two emerging platforms. These are:

• Desktop Widgets: These widgets run on your computer desktop
• Web Widgets: These widgets run on a web page, blog or social network
• Mobile Widgets: These widgets run on your mobile phone
• TV Widgets: These widgets run on your TV set

Web widgets are either universal (run on most web pages) or platform-specific (run within a specific web environment such as iGoogle, widgetbox or Netvibes). Web widgets are generally written in Adobe Flash or Javascript/HTML. Some platform-specific widgets also have an XML component.

Desktop widgets usually run on a specific widget platform. These platforms are either OS platform-specific (Windows Vista, Macintosh OS, i.e.) or use a widget engine (such as Yahoo Widgets!, Opera, i.e.).  As I mentioned, the "widget engine" can be part of the operating system (Vista, Mac) or run on multiple operating systems. Third party widget engines that run on multiple platforms (Yahoo Widgets!, Opera) must be downloaded and installed by the end-user, which an be a barrier to distribution.  You can also have "native" Windows or Macintosh widgets, which are essentially stand alone applications than run on specific operating systems.  These "native" widgets, though rare, are usually written to address operating systems than do not come with a built-in widget platform (Windows XP).

Mobile Widgets, as the name implies, run on mobile phones (primarily the iPhone, Blackberry, Windows Mobile devices and the Nokia S60). Several mobile platforms are available. Yahoo Mobile widget platform runs on the iPhone, Windows Mobile devices and the Nokia S60 phone! Yahoo is one of few companies to support third-party mobile widget. Widgets are also available on Opera's Mobile 9.5 platform which runs on Windows Mobile, Nokia S60, and UIQ. Additionally, MOTODEV Studio for WebUI from Motorola allows you to deploy widgets on Motorola's open mobile Linux platform using Java ME, UIQ and Native Linux.

TV Widgets represent a emerging new platform recently announced by Yahoo! and Intel. Yahoo is currently the only platform with plans to support TV widgets on certain HDTV models from Samsung, Vizio, LG Electronics, and Sony. TV widgets will live at the bottom of your TV screen and will be turned on or off with one click of the button! Initial widgets will include the obvious news, weather, stocks, sports and photos (Flickr).

For a complete, more comprehensive list of widget platforms visit: http://go.metablocks.com/widget-platforms