This is MongoDB's fork of Apache Lucene, maintained for use by mongot.

The main branch, development branches (e.g. branch_10x, branch_10_3, branch_9_11) and release tags (e.g. releases/lucene/10.3.2, releases/lucene/9.11.1) track upstream Lucene. Mongot development branches (e.g. mongot_9_11_1) are created from uptream release tags and contain Mongot commits. See scripts/release/ for the tooling that creates these branches and their corresponding Evergreen projects.

Apache Lucene is a high-performance, full-featured text search engine library written in Java.

This README file only contains basic setup instructions. For more comprehensive documentation, visit:

• Latest Releases: https://lucene.apache.org/core/documentation.html
• Nightly: https://ci-builds.apache.org/job/Lucene/job/Lucene-Artifacts-main/javadoc/
• New contributors should start by reading Contributing Guide
• Build System Documentation: help/
• Migration Guide: lucene/MIGRATE.md

1. Install JDK 25 using your package manager or download manually from OpenJDK, Adoptium, Azul, Oracle or any other JDK provider.
2. Clone Lucene's git repository (or download the source distribution).
3. Run gradle launcher script (gradlew).

We'll assume that you know how to get and set up the JDK - if you don't, then we suggest starting at https://jdk.java.net/ and learning more about Java, before returning to this README.

External contributions are currently not accepted in this repository. If you'd like to contribute to Lucene, please see the upstream project at https://github.com/apache/lucene.