Steve Lay HeadshotPosted by Steve Lay
Last year I wrote a quick primer on the OData protocol and how it relates to Questionmark’s Open Assessment Platform, see What is OData and Why is it important?
A lot has happened in the last year in the OData community. One of the most interesting aspects of the developing standard is the way the OData ‘ecosystem’ is developing. This is the term used to describe the tools that developers can use to help them support the standard as well as the data services published by information providers.
The OData specification started life at Microsoft, but the list of contributors to the OASIS technical committee now includes some other familiar names such as IBM and SAP. SAP are co-chairing the technical committee and have made a significant contribution to an open source library that allows Java developers to take advantage of the standard. This library has recently been moved into an Apache Foundation ‘incubator’ which is a great way to get the Java developer community’s attention. You can find it at Apache Olingo.
Moving the specification into an industry standards body like OASIS means that Microsoft relinquish some control in exchange for a more open approach. OASIS allows any interested party to join and become part of the standards development process. Documentation is now available publicly for review before it is finalized, and I’ve personally found the committee responsive.
Microsoft continue to develop tools that support OData both through Windows Communication Foundation (WCF) and through the newer WebAPI, making OData a confirmed part of their platform. There are options for users of other programming languages too. Full details are available from
With OASIS now in the process of approving version 4 of the specification, I thought it would be worth giving a quick overview of how Questionmark is using the standard and how it is developing.
Questionmark’s OData API for Analytics uses version 2 of OData. This is the most widely supported version of the specification; it is also the version supported by Apache Olingo.
Some of the more recent libraries, including Microsoft’s WCF and Web API, have support for version 3 of the protocol. We’re currently investigating the potential of version 3 for future OData projects at Questionmark.
Version 4 is the first version published by OASIS and marks an important step for the OData community. It also brings in a number of breaking changes, in the words of the technical committee:
“In evolving a specification over time, sometimes you find things that worked out better than you had expected and other times you find there are things you wish you had done differently.”
Ref: What’s new in OData 4
The reality is that there are lot of new features in version 4 of the protocol and, combined with comrehensive clean-up process, it will be some time before version 4 is widely adopted across the community. However, the increased transparency that comes with an OASIS publication and the weight of industry leaders like SAP to help drive adoption mean it is definitely one I’ll be keeping an eye on.