The WCF Data Services Toolkit is a set of extensions to WCF Data Services (the .NET implementation of OData) that attempt to make it easier to create OData services on top of arbitrary data stores without having deep knowledge of LINQ.
It was born out of the needs of real-world services such as Netflix, eBay, Facebook, Twitpic, etc. and is being used to run all of those services today. We've proven that it can solve some interesting problems, and it's working great in production, but it's by no means a supported product or something that you should take a hard commitment on unless you know what you're doing.
In order to know whether you qualify for using the toolkit to solve your solution, you should be looking to expose a non-relational data store (EF + WCF Data Services solves this scenario beautifully) as an OData service. When we say "data store" we really do mean anything you can think of (please be responsible though):
- An XML file (or files)
- An existing web API (or APIs)
- A legacy database that you want to re-shape the exposed schema dramatically without touching the database
- A proprietary software system that provides its data in a funky one-off format
- A cloud database (e.g. SQL Server) mashed up with a large schema-less storage repository (e.g. Windows Azure Table storage)
- A CSV file zipped together with a MySQL database
- A SOAP API combined with an in-memory cache
- A parchment scroll infused with Egyptian hieroglyphics
That last one might be a bit tricky though...
WCF Data Services provides the functionality for building OData services and clients on the .NET Framework. It makes adding OData on top of relational and in-memory data very trivial, and provides the extensibility for wrapping OData on top of any data source. While it's possible, it currently requires deep knowledge of LINQ (e.g. custom IQueryables and Expression trees), which makes the barrier of entry too high for developing services for many scenarios.
After working with many different developers in many different industries and domains, we realized that while lots of folks wanted to adopt OData, their data didn't fit into that "friendly path" that was easily achievable. Whether you want to wrap OData around an existing API (SOAP/REST/etc.), mash-up SQL Azure and Windows Azure Table storage, re-structure the shape of a legacy database, or expose any other data store you can come up with, the WCF Data Services Toolkit will help you out. That doesn't mean it will make every scenario trivial, but it will certainly help you out a lot.
In addition to this functionality, the toolkit also provides a lot of shortcuts and helpers for common tasks needed by every real-world OData service. You get JSONP support, output caching, URL sanitization, and more, all out of the box. As new scenarios are learned, and new features are derived, we'll add them to the toolkit. Make sure to let us know about any other pain points you're having, and we'll see how to solve it.