The Library of Congress SRW API provides a standard for search queries. SRW (Search/Retrieve Web Service) is a variation of SRU (Search/Retrieve via URL). Rather than conveying messages from client to server over URL, it uses XML over HTTP via SOAP as per W3C recommendations. This specification tries to comply with Web Services Interoperability recommendations.
The following is a list of SDKs from our SDK directory that matched your search term. Though your definition of an SDK may differ, in our world, we define SDKs as platform- specific tools for consuming existing APIs of the sort we list in our API directory. For example, the Ruby SDK for consuming the Twitter Ads API. If you think an SDK, API, or other asset is missing from our directory, be sure to check our guidelines for making contributions to ProgrammableWeb.