I have been getting alot of questions about what oData is so this post is intended to provide a little detail on the topic.
The Open Data Protocol (OData) is an open protocol for sharing data. It provides a way to break down data silos and increase the shared value of data by creating an ecosystem in which data consumers can interoperate with data producers in a way that is far more powerful than currently possible, enabling more applications to make sense of a broader set of data. Every producer and consumer of data that participates in this ecosystem increases its overall value.
Data has become a first-class element of the web. The Open Data Protocol (OData) applies web technologies such as HTTP, AtomPub and JSON to enable a wide range of data sources to be exposed on the web in a simple, secure and interoperable way. Whether you have a simple collection of reference data, are building a Rich Internet Application or are building the web API for your web property, the Open Data Protocol enables you to expose your data and its associated logic as an OData feed. Once your data is available as an OData feed it can be consumed by any of the available OData-aware developer libraries/tools, business intelligence products, visualization components, etc.
The Open Data Protocol specification is currently available under the Microsoft Open Specification Promise (OSP), allowing third parties, including open source projects, to build Data Services for any runtime as well as clients to consume such services.
Here are some good links on the topic;