Associations Indexing Service (AIS) was originally done as an extension of human memory for tagging (storing under personal keywords and associations) resources, URIs, bookmarks, and memos (for fast access to the information in future) by using the same keywords or queries, similar to popular search engines.
It can be seen as a local search engine, used as an automatic indexer of big file hierarchies (e.g. personal archives or files repositories). It is based on Lucene, so the application will remain very fast with any size index.