As was announced at the ESRI UC, the GeoServices REST Specification, Version 1.0 has hit the streets.

Services that follow the specification will “speak the same language” as the REST-ful Esri Web services. That means clients can consume them with the popular ArcGIS APIs for JavaScript, Flex, Silverlight, iOS, and Android; as well as other Esri client APIs. However, you don’t have to own or use any Esri software in order to implement the specification or to build a client that works with the services.

As you examine the specification, you’ll probably notice that it looks like the ArcGIS REST API. This is deliberate. The pattern we have used at Esri for exposing REST-ful GIS services has been embraced by thousands of developers who use the ArcGIS Web APIs. It is a simple and intuitive way of structuring and talking to GIS Web services. We wanted you to feel free to implement services that follow the same pattern.

Whether or not this is truly an open spec (and  not opening the debate as to how “RESTful” this spec really is), the rush begins for everyone to implement this spec on their own apps so they can be used with ESRI clients.