B+-tree using Memory Mapped Files, supports range queries and duplicate keys

Small string compression library

Streaming library supporting reuse and many operators

Guava is a suite of core and expanded libraries that include

A fast SQL database that can run embedded or a server mode with support for transactions, encryption, full search, etc. ...

The Apache Commons IO library contains utility classes, stream implementations, file filters,

Apache Ant is a Java library and command-line tool whose mission is to drive processes described in build files as ...

API for Jakarta Servlet, enabling web applications to handle HTTP requests and responses through a standard interface ...

JUnit Jupiter is the API for writing tests using JUnit 5.