The Appkit library of search application components has simple building blocks that can be put together to build complex applications for search and information retrieval.
Appkit provides a generic API for searching and indexing content that completely abstracts the search engine or database in use. This means the application developer does not need to know the ins and outs of each search and database technology, but instead only needs to know how to work with Appkit.
At the most fundamental level:
Appkit sends generic queries (which are platform independent) to a platform that translates them into something the underlying search engine can work with.
Appkit maps the response from the search engine to a generic Appkit search response which other components can work with and that Appkit UI widgets can render.