Application Programming Interface
From Unofficial BOINC Wiki
[edit] General
Abbreviated as API.
A defined set of interfaces and the protocols that may use them and how this will alter the computer, Operating System, or application programs behavior. Commonly used to control software systems and to provide for the abstraction of the software system so that the various parts can be seen as a software "black boxes". Changes to the internal software within these software modules should not change the way in which the external software "sees" the software component.
Changes to the API will of course have an impact on the other software components that have been programmed to use the interfaces. In these cases, one of the ways this is mitigated is by the use of extensions and a new API that offers the greater capabilities until the other software components can be re-coded to use the newer API. In practice it can take decades to accomplish this. In many cases, once created and published, an API seems to "live" forever.
