NSFW.js (GitHub Repo)
NSFW.js allows for client-side content filtering, meaning that image files can be classified before it reaches the server. It classifies images into one of 5 categories: drawing, hentai, neutral, porn, or sexy, and also gives a probability ratio for each image classification. The tool is around 90% accurate, and can lesser server load as well as workload, stopping users from uploading images which may not be appropriate for your website.
Halley Game Engine (GitHub Repo)
Halley is a lightweight game engine written in C++ designed to create high performance, easy to maintain, cross-platform games. It has been tested on Windows 10 Professional 64-bit, Mac OS 10.9.6, and Ubuntu 16.04. Full documentation is not yet available for the engine.