Ghidra is a software reverse engineering (SRE) framework

Termux - a terminal emulator application for Android OS extendible by variety of packages.

Google core libraries for Java

Free universal database tool and SQL client

Dex to Java decompiler

A libre lightweight streaming front-end for Android.

Open Source Identity and Access Management For Modern Applications and Services

Telegram for Android source

The automation tower defense RTS

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.

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

QuestDB is a high performance, open-source, time-series database

A Java 8+ Jar & Android APK Reverse Engineering Suite (Decompiler, Editor, Debugger & More)

Cryptomator for Windows, macOS, and Linux: Secure client-side encryption for your cloud storage, ensuring privacy and control over your data.

Arduino IDE 1.x

Style and Grammar Checker for 25+ Languages

Tools to work with android .dex and java .class files

Generate diagrams from textual description

Official repository of Trino, the distributed SQL query engine for big data, formerly known as PrestoSQL (https://trino.io)

A free, secure and open source app for Android to manage your 2-step verification tokens.

Redis Java client

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

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

Efficient reliable UDP unicast, UDP multicast, and IPC message transport

Apache Tomcat

Tiny, easily embeddable HTTP server in Java.

The modern Java bytecode editor

Digital logic design tool and simulator

Open source routing engine for OpenStreetMap. Use it as Java library or standalone web server.