The Simple API for Grid Applications (SAGA) is a family of related standards specified by the Open Grid Forum to define an application programming interface (API) for common distributed computing functionality. Overview The SAGA specification for distributed computing originally consisted of a single document, GFD.90, which was released in 2009. The SAGA API does not strive to replace Globus or similar grid computing middleware systems, and does not target middleware developers, but application developers with no background on grid computing. Such developers typically wish to devote their time to their own goals and minimize the time spent coding infrastructure functionality. The API insulates application developers from middleware. The specification of services, and the protocols to interact with them, is out of the scope of SAGA. Rather, the API seeks to hide the detail of any service infrastructures that may or may not be used to implement the functionality that the application developer needs. The API aligns, however, with all middleware standards within Open Grid Forum (OGF). The SAGA API defined a mechanism to specify additional API packages which expand its scope. The SAGA Core API itself defines a number of packages: job management, file management, replica management, remote procedure calls, and streams. SAGA covers the most important and frequently used distributed functionality and is supported and available on every major grid systems - Extreme Science and Engineering Discovery Environment (XSEDE), EGI and FutureGrid. SAGA not only supports a wide range of distributed programming and coordination models but is also easily extensible to support new and emerging middleware. Standardization The SAGA API is standardised in the SAGA Working Group the Open Grid Forum. Based on a set of use cases , the SAGA Core API specification defines a set of general API principles (the 'SAGA Look and Feel', and a set of API packages which render commonly used Grid programming patterns (job management, file management and access, replica management etc.) The SAGA Core specification also defines how additional API packages are to be defined, and how they relate to the Core API, and to its 'Look and Feel'. Based on that, a number of API extensions have been defined, and are in various states of the standardisation process. All SAGA specifications are defined in (a flavor of) IDL, and thus object oriented, but language neutral. Different language bindings exist (Java, C++, Python), but are, at this point, not standardised. Nevertheless, different