Apache Pulsar - distributed pub-sub messaging system

Code for Quartz Scheduler

JSqlParser parses an SQL statement and translate it into a hierarchy of Java classes. The generated hierarchy can be navigated using the Visitor Pattern

Distributed Graph Database

MapDB provides concurrent Maps, Sets and Queues backed by disk storage or off-heap-memory. It is a fast and easy to use embedded Java database engine.

Distributed lock for your scheduled tasks

Benchmark comparing serialization libraries on the JVM

Port of LevelDB to Java

Persistent cluster-friendly scheduler for Java

Feature Flags for Java made easy

Secure and speedy templates for Java and Kotlin.

DAO oriented database mapping framework for Java

A fast key/value store that is efficient for high-volume random access reads and writes.

Scalable Java Redis client

Java 8+ zero-dependency port of SymSpell: 1 million times faster through Symmetric Delete spelling correction algorithm