DEFINITION: Machine to Machine Interface ABB is an Application Interface enabling the exchange of data between a service and other services. This ABB is a key interoperability enabler (*) for assessing compatible interfaces. Source: ISA2 - EIA Action (https://ec.europa.eu/isa2/eif_en.) (*)DECISION (EU) 2015/2240 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 25 November 2015 establishing a programme on interoperability solutions and common frameworks for European public administrations, businesses and citizens (ISA2 programme) as a means for modernising the public sector. INTEROPERABILITY SALIENCY: IoP Dimension: Behavioral IoP The Machine to Machine Interface ABB is a key interoperability enabler because it supports to achieve technical behavioral interoperability by enabling the exchange of data, information, and knowledge between digital public services as stated in the EIF recommendation n°5: ""Ensure internal visibility and provide external interfaces for European public services" and recommendation n°9:"Ensure data portability, namely that data is easily transferable between systems and applications supporting the implementation and evolution of European public services without unjustified restrictions, if legally possible." EXAMPLES: The following implementation is an example on how this specific Architecture Building Block (ABB) can be instantiated as a Solution Building Block (SBB): XMLGate TRACES Businesses (XTB) Webservices enabling the management of organisations and cities registered in TRACES. Source: (https://circabc.europa.eu/sd/a/dc77e52b-dfba-4dcc-aa39-6a54748db01d/XmlGate%20TRACES%20Businesses%20Manual.doc) In addition, the European Commission has publiched a study, called APIs4DGov, on Web Application Programming interfaces (APIs). The study identifies and describes a set of API standards and technical specification which can be used for Machine to Machine interfaces, as an example: Advanced Message Queuing Protocol (AMQP); Application Performance Index (APDEX); HAL-FORMS. Source: study lists 80 APIs standards (https://ec.europa.eu/knowledge4policy/node/35863_el)