Microsoft today published its “REST API Design Guidelines” to the API community. These guidelines represent a multi-year, cross-company, collaborative process aggregating the collective experience of hundreds of engineers designing, operating, and running global scale cloud services from across Microsoft; and listening to feedback on APIs from its customers and partners. They have attempted to incorporate those learnings along with industry best practices in the API space to create guidelines that API teams across Microsoft use on a daily basis.
The Microsoft REST API Guidelines, as a design principle, encourages application developers to have resources accessible to them via a RESTful HTTP interface. To provide the smoothest possible experience for developers on platforms following the Microsoft REST API Guidelines, REST APIs SHOULD follow consistent design guidelines to make using them easy and intuitive.
You can find the Microsoft REST API Guidelines on GitHub: http://www.GitHub.com/microsoft/api-guidelines/.