Carrot2 is a programming library for clustering text. It can automatically discover groups of related documents and label them with short key terms or phrases.
Carrot2 can, for example, organize search results into groups like these:
Search result titles and snippets (on the left) for query "salsa" and corresponding cluster labels (right).
Carrot2 provides a common infrastructure and a number of algorithms for clustering of text. Out-of-the-box, Carrot2 distribution comes with:
Additionally, several downstream projects provide integration between Carrot2 and popular document retrieval services: