OpenMW is an open-source open-world RPG game engine that supports playing Morrowind. Main repo and issue tracker can be found here: https://gitlab.com/OpenMW/openmw/

Synapse: Matrix homeserver written in Python/Twisted.

Apache ECharts is a powerful, interactive charting and data visualization library for browser

Open-source JavaScript charting library behind Plotly and Dash

This is the Rust course used by the Android team at Google. It provides you the material to quickly teach Rust.

Godot Engine – Multi-platform 2D and 3D game engine

Parsing gigabytes of JSON per second : used by Facebook/Meta Velox, the Node.js runtime, ClickHouse, WatermelonDB, Apache Doris, Milvus, StarRocks

Free and Open Source Machine Translation API. Self-hosted, offline capable and easy to setup.