# apache/lucene

Apache Lucene open-source search software

Repository: https://github.com/apache/lucene
Canonical: https://ross.abutalabs.com/products/lucene
Homepage: https://lucene.apache.org/
Language: Java
License: Apache-2.0
License Family: permissive
Topics: lucene, search, nosql, java, backend, search-engine, information-retrieval
Last push: 2026-08-26T19:42:22+00:00

## Health v2 (maintenance only)
Score: 94/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 85, longevity 100
- inputs: {"age_days": 2017, "days_push": 7, "days_rel": 21, "gap_med": 44.0, "n_releases_24m": 15}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3550, forks 1422 (observed 2026-08-28T04:08:09.548262+00:00)

## What it is
Apache Lucene is a high-performance, full-featured text search engine library written in Java, providing indexing, search, spellchecking, hit highlighting, and advanced analysis/tokenization. It is the search core underlying Apache Solr, Elasticsearch, and OpenSearch, with a PyLucene Python binding also available.

## Use cases
- add full-text search to my application
- build an inverted index over documents
- implement ranked keyword search with highlighting
- add autocomplete and spell correction to search
- embed a search engine in a Java backend
- index and query millions of documents fast

## When to choose
- you need a fast, embeddable search library in the JVM ecosystem
- you are building your own search server or database on top of a proven core
- you need fine-grained control over indexing, analysis, and scoring

## When to avoid
- you want a ready-to-run search server with REST APIs - use Solr, Elasticsearch, or OpenSearch instead
- your project is not on the JVM and PyLucene bindings are insufficient
- you only need simple database full-text search features

## Facets
- artifact type: library
- maturity: stable
- function: search-engine, parser, nlp
- domain: databases, developer-tools
- platform: jvm, cross-platform
- tags: full-text-search, indexing, information-retrieval, tokenization, spellchecking, hit-highlighting, vector-search, pylucene, search

## Member repositories
- apache/lucene (main) score 94

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:09.548262+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:34:21.187542+00:00, confidence not recorded.
  - readme: https://github.com/apache/lucene (fetched 2026-08-28T04:08:09.548262+00:00, sha 5ab54445ff3a)
  - homepage: https://lucene.apache.org/ (fetched 2026-08-29T09:28:15.793361+00:00, sha a3009cd4a31e)
- Data as of 2026-08-30T08:39:29.467469+00:00.