An open platform in software is often called an API, which stands for application programming interface. An API is a kind of lingua franca that software applications can use reliably to communicate with each other, a set of standardized rules and definitions that allow programmers to build new tools on top of another platform, or to weave together information from multiple platforms. When Web users make geographic mashups using Google Maps, they write programs that communicate with Google’s geographic data using their mapping API.
