Last year, Yelp introduced its completely new Yelp Fusion API. Since its introduction, Yelp has dedicated most of its resources on the new API, and encouraged developers to migrate to Fusion. Over that time period, Yelp has added new features, fixed bugs, and now signals the end of the legacy API.
In response to much feedback from the developer community, Microsoft has revamped the Bing Search APIs with a long list of new features. Not only do the new features expand the possibilities for using Bing within an app, a modern architecture should streamline integration and ease maintenance.