API

from The Free On-line Dictionary of Computing (8 July 2008)

Application Program Interface
API
Application Programming Interface
Applications Programming Interface

   <programming> (API, or "application programming interface")
   The interface (calling conventions) by which an {application
   program} accesses {operating system} and other services.  An
   API is defined at {source code} level and provides a level of
   {abstraction} between the application and the {kernel} (or
   other privileged utilities) to ensure the {portability} of the
   code.

   An API can also provide an interface between a {high level
   language} and lower level utilities and services which were
   written without consideration for the {calling conventions}
   supported by compiled languages.  In this case, the API's main
   task may be the translation of parameter lists from one format
   to another and the interpretation of {call-by-value} and
   {call-by-reference} arguments in one or both directions.

   (1995-02-15)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

API
       Application Program Interface (API)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

API
       Associacao Portuguesa de Informatica (org., Portugal)