Apache Solr

Apache Solr, developed by the Apache Software Foundation, is an open-source enterprise search platform built on Apache Lucene that indexes and searches vast data volumes with high speed and sub-second response times.

Two-hop subgraph: this entity, every entity it directly relates to, and every entity those neighbors relate to. Drag a node, scroll to zoom, click to inspect — or click any neighbor and re-center the atlas there.