The document discusses Apache UIMA, an architectural framework for managing unstructured data. It is not inherently a semantic search tool. It allows for pluggable analysis engines and asynchronous scaleout. The document provides examples of how UIMA can be used for semantic search, including generating metadata for content management systems, data enrichment, and linking to external data sources. It also describes how AlchemyAPI services can be wrapped as UIMA components to perform named entity recognition and linking to knowledge bases.