The Math project is a library of lightweight, self-contained mathematics and statistics components addressing the most common practical problems not immediately available in the Java programming language or commons-lang.

Apache Hadoop Common

The core Java API for building stream processing applications with Apache Flink.

All of the recipes listed on the ZooKeeper recipes doc (except two phase commit).

Hive Query Language

Unit testing utilities.

Infinispan core module

Server functionality for HBase

Apache HBase™ is the Hadoop database. Use it when you need random, realtime read/write access to your Big Data.

Interfaces to be implemented in order to smooth over hadoop version differences

Apache Accumulo core libraries.