Marauroa

Marauroa is Arianne's Multiplayer Online Engine, which you can use to build your own online games. Marauroa handles object management, asynchronous database persistence and perception based client-server communication.

Box2D

A 2D Physics Engine for Games

LibGDX

LibGDX是一个跨平台的2D/3D的游戏开发框架，它由Java/C/C++语言编写而成。

Chartsy

Open Source stock charting, screening and trading platform

bitcoinj

bitcoinj is a library for working with the Bitcoin protocol. It can maintain a wallet, send/receive transactions without needing a local copy of Bitcoin Core and has many other advanced features. It's implemented in Java but can be used from any JVM compatible language: examples in Python and JavaScript are included.