From their site: The Google Gadgets API provides a way to put third-party content onto the Google homepage. The main use of the Google Gadgets API is to create gadgets (mini-applications) that users can add to their Google personalized homepages and other Google properties. For example, you could create a photo album gadget, or a gadget that displays an interactive game. The API is designed to be simple enough so that anyone can turn his or her web page or application into a gadget.
The following is a list of SDKs from our SDK directory that matched your search term. Though your definition of an SDK may differ, in our world, we define SDKs as platform- specific tools for consuming existing APIs of the sort we list in our API directory. For example, the Ruby SDK for consuming the Twitter Ads API. If you think an SDK, API, or other asset is missing from our directory, be sure to check our guidelines for making contributions to ProgrammableWeb.