Sunshine is a self-hosted, cross-platform game streaming server that implements the NVIDIA GameStream protocol, enabling remote play via Moonlight clients. It captures the host's display (using platform-specific backends such as DXGI, Wayland, X11, KMS, or PipeWire), encodes video with hardware acceleration (NVENC, VAAPI, Vulkan, AMF, QuickSync, or software), and forwards input (keyboard, mouse, gamepad, touch) from the client to the host. The server also provides a web-based configuration UI, handles client pairing with X.509 certificates and AES encryption, and manages streaming sessions via RTSP. It supports HDR, surround audio, gamepad feedback, and network QoS. Architecturally, Sunshine is a monolithic C++ application with a modular platform abstraction layer. The core components include an HTTP/HTTPS server for pairing and configuration, an RTSP server for session setup, and UDP broadcast threads for video, audio, and control data. The codebase is heavily optimized for low-latency streaming, featuring thread-safe queues, a generic task pool, and RAII resource management. It integrates with Boost, FFmpeg, libcurl, and various hardware encoder SDKs, and is packaged for Windows, Linux, macOS, and FreeBSD via multiple distribution channels. The repository demonstrates strong engineering practices with extensive unit and integration tests, consistent coding style, and active maintenance. While some files are large and platform-specific, the core utility modules are cleanly separated and reusable. The project is not a data/research repository; it is a production-grade application for game streaming enthusiasts and developers.