The United States Department of Agriculture (USDA) has just launched the brand new USDA Farmers Market Directory API providing developers programmatic access to the USDA National Farmers Market Directory database. According to the USDA website, the National Farmers Market Directory has over 7,800 farmers market listings for all 50 states and provides consumers farmers market information such as market locations, directions, operating times, product offerings, and accepted forms of payment.
A project of the Elgg Foundation, Elgg is a free open source social networking engine licensed to users under the GNU Public License v2. The REST Elgg API allows developers to integrate Elgg and offer new apps for it. To give a sense of its size, 1,646 plugins have been created so far by the user community, with nearly 3 million downloads. Examples of plugins include blogs, forums, social bookmarks.
Popular social check-in service Foursquare is going through some changes, and the most important of those is that the old v1 API is going dead, as we've known since March. Older apps, especially abandoned ones, will stop working then, as will any newer app that hasn't yet upgraded to the new API.