Yesterday Google announced that it is turning its acquisition of Gapminder last year into more free data goodness; this time, it’s making an API available to more or less standard data visualization tools.
In this context don’t think of visualization as ray casting and streaklines; what Google is talking about here is visualization of the type to be found in Excel.
With the Google Visualization API, you can access structured data from supported data sources and receive a response in a simple tabular format. The format is amenable to use by reporting, analysis or visualization application. You can thus visualize the data and/or add new functionality to applications, such as Google Spreadsheets.
In fact, Google Spreadsheets supports the Visualization Gadgets built on the Visualization API. Gadgets can also be embedded on iGoogle for live rendering of data streams.
Visualization gadgets read data from a data source, and display this data in a useful way. The data source is typically configured in a gadget as a URL in a gadget preference called data source URL.