At F8 -- Facebook's annual developer conference -- the company's engineers announced a new version of React with a core designed to optimize the performance of applications that are written with the framework. The new core, React Fiber, is better at scheduling tasks based on what the user is doing.
When it comes to map mashups there's no doubt that Google Maps leads the way. On ProgrammableWeb we list 1,964 Google Maps mashups, almost four times as many as any other API. This popularity makes utilities built on top of Google Maps especially interesting, such as this contextual menu control, which pops up a menu when the user right clicks.