Open Data Protocol (OData) is an open protocol to allow the creation and consumption of queryable and interoperable RESTful APIs in a simple and standard way.
It's initiated by Microsoft in year 2007.
Versions 1.0, 2.0, and 3.0 are released under the Microsoft Open Specification Promise.
Version 4.0 was standardized at OASIS, with a release in March 2014.
In April 2015, OASIS has further Submitted OData v4 and OData JSON Format v4 to ISO/IEC JTC 1 for approval as an International Standard.
The protocol enables the creation and consumption of REST APIs, which allow resources, identified using URLs and defined in a data model, to be published and edited by Web clients using simple HTTP messages. It shares some similarity with JDBC and ODBC but OData is not limited to relational databases.