The Sindice API provides programmatic access to its semantic search capabilities. It is based on the OpenSearch spec. Over 10 billion pieces of data can already be searched within 100 million web pages with embedded RDF and Microformats. For example you can build on the API and find RDF with a certain "foaf:name" value.
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.