WCF Data Services vs WCF RIA Services

I’ve been having trouble finding a straight forward comparison of these two technologies. On the surface they appear to be solving similar, if not the same problems.

Make no mistake – the message coming from Microsoft is not clear or consistent – which probably explains the confusion. I suspect the relationship between these two products is still being “discovered” by MS.

Anyway, in this bliki I will try to sum up my findings as to the differences between them as I figure them out.

WCF (ADO.NET) Data Services	WCF (.NET) RIA Services
Expose data model as RESTful web service	Prescriptive approach to n-tier app development
Cross platform interoperation as a goal - “Unlock data silos” - Out-of-box support from future MS products such as SQL2008 R2, Azure, Excel 2010, SharePoint 2010	Designed specifically for end-to-end Silverlight & ASP.NET solutions - Some technology proprietary to Silverlight (no WPF support) - Use ASP.NET Authentication/Roles across SL and ASP.NET - ASP.NET/AJAX can also access service layer
Loosely coupled clients and servers	Client & server are designed and deployed together
Service layer exposes “raw” data sources	Opportunity to easily add business logic into service layer - Encourage “domain” concepts - Strong validation framework - Offline / Sync enabled
Service can be consumed from .NET, Silverlight, AJAX, PHP and Java (libraries available)	Service can be consumed easily from SL, AJAX, WebForms
Service’s data source must: - Expose at least one IQueryable property - Implement IUpdateable if you desire updates	Service exposes domain objects via convention: - IQueryable GetX - UpdateX/InsertX/DeleteX
No design time experience yet (??)	Design time experience with data sources, drag drop etc
- OData for all clients - Within OData, multiple formats supported (JSON, XML etc)	- SOAP (binary) for SL clients - JSON for AJAX clients - SOAP (XML) for other clients
Discoverable (?)	Non-discoverable
Hosted as WCF Service (.svc)	Old version hosted in custom web handler (.axd). New version is WCF service.
Standardized on OData protocol	Will “support” OData
More mature – public for at least 2 years, formerly “Project Astoria”	Less mature - public for 6 months