OASIS has just announced a technical committee for standardising search services. This from the Call for Participation:
To define Search and Retrieval Web Services, combining various current and
ongoing web service activities.
Within recent years there has been a growth in activity in the development of
web service definitions for search and retrieval applications. These include
SRU, a web service based in part on the NISO/ISO Search and Retrieval standards;
the Amazon OpenSearch, which defines a means of describing and automating search
web forms; as well as many proprietary definitions (e.g. the Google and MSN
Search APIs). There are also a number of activities for defining abstract search
APIs that can be mapped onto multiple implementations either within native code
or onto remote procedural calls and web services, such as ZOOM (Z39.50 Object
Oriented Model); SQI (Simple Query Interface), an IEEE standard developed for
searching and retrieval in the IMS (Instructional Management Systems) space; and
OSIDs (Open Service Interface Definitions from the Open Knowledge Initiative.
While abstract APIs would be out of scope, these would inform the work to
increase interoperability and compatibility.