RxJava – Reactive Extensions for the JVM – a library for composing asynchronous and event-based programs using observable sequences for the Java VM.

A type-safe HTTP client for Android and the JVM

Getting Started with Spring Boot 3:

Open Source Identity and Access Management For Modern Applications and Services

Render After Effects animations natively on Android and iOS, Web, and React Native

ZXing ("Zebra Crossing") barcode scanning library for Java, Android

Apache Flink

Hystrix is a latency and fault tolerance library designed to isolate points of access to remote systems, services and 3rd party libraries, stop cascading failure and enable resilience in complex di…

JDK main-line development https://openjdk.org/projects/jdk

光 HikariCP・A solid, high-performance, JDBC connection pool at last.

A high performance caching library for Java

A fast dependency injector for Android and Java.

Modern Java - A Guide to Java 8

Quarkus: Supersonic Subatomic Java.

Open source alternative to Auth0 / Firebase Auth / AWS Cognito

Vert.x is a tool-kit for building reactive applications on the JVM

🏗 Build container images for your Java applications.

Suite of tools for deploying and training deep learning models using the JVM. Highlights include model import for keras, tensorflow, and onnx/pytorch, a modular and tiny c++ library for running mat…

Apache Druid: a high performance real-time analytics database.

Guice (pronounced 'juice') is a lightweight dependency injection framework for Java 11 and above, brought to you by Google.

The Java gRPC implementation. HTTP/2 based RPC

Java JWT: JSON Web Token for Java and Android

The Clojure programming language

A barebones WebSocket client and server implementation written in 100% Java.

Resilience4j is a fault tolerance library designed for Java8 and functional programming

CoreNLP: A Java suite of core NLP tools for tokenization, sentence segmentation, NER, parsing, coreference, sentiment analysis, etc.

Feign makes writing java http clients easier

Spinnaker is an open source, multi-cloud continuous delivery platform for releasing software changes with high velocity and confidence.

A simple expressive web framework for java. Spark has a kotlin DSL https://github.com/perwendel/spark-kotlin

1️⃣🐝🏎️ The One Billion Row Challenge -- A fun exploration of how quickly 1B rows from a text file can be aggregated with Java