Ghidra is a software reverse engineering (SRE) framework

Dex to Java decompiler

Desktop/Android/HTML5/iOS Java game development framework

FizzBuzz Enterprise Edition is a no-nonsense implementation of FizzBuzz made by serious businessmen for serious business purposes.

GraalVM compiles Java applications into native executables that start instantly, scale fast, and use fewer compute resources 🚀

An Android library for managing images and the memory they use.

Arduino IDE 1.x

A declarative API to handle Android runtime permissions.

A Java API for generating .java source files.

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

Java Native Access

An Android library supports badge notification like iOS in Samsung, LG, Sony and HTC launchers.

Modifications to the Minecraft base files to assist in compatibility between mods. New Discord: https://discord.minecraftforge.net/

A Java to iOS Objective-C translation tool and runtime.

🚀 A Complete Fast Android Networking Library that also supports HTTP/2 🚀

Install and run GNU/Linux on Android

Thumbnailator - a thumbnail generation library for Java

Joda-Time is the widely used replacement for the Java date and time classes prior to Java SE 8.

Open-Source Subscription Billing & Payments Platform

Allows Android apps to interact with BLE beacons

The missing Java distribution of native C++ libraries

Compiles Java bytecode to JavaScript, WebAssembly and C

Custom Android RecyclerViewAdapters that collapse and expand

Copybara: A tool for transforming and moving code between repositories.

A cross-platform G-Code sender for GRBL, Smoothieware, TinyG and G2core.

Cross-platform framework for building truly native mobile apps with Java or Kotlin. Write Once Run Anywhere support for iOS, Android, Desktop & Web.

For more info see

BusyBox for Android

Cross-platform static analyzer and linter for Swift.

XobotOS - Android ported to C#