RanGDI

RanGDI is a proposed open-source graphics library that provides an abstraction layer for the Windows Graphics Device Interface (GDI) and related rendering APIs. The project aims to enable cross-platform GUI development by offering a unified API that can be mapped to native backends on Windows, Linux, and macOS, while preserving GDI-compatible semantics for rendering, clipping, and font handling.

Key capabilities include a compatibility subset of common GDI functions, a pluggable backend architecture, and efficient resource management for device contexts, bitmaps, and fonts. It supports both raster and vector primitives, coordinate transformations, and basic text rendering, with attention to backward compatibility for legacy Windows applications.

Architecture comprises a client-facing API, a backend layer that implements platform-specific rendering, and an abstraction layer for device contexts and drawing primitives. Backends may map GDI calls to native APIs such as Windows GDI, Core Graphics on macOS, or Cairo/Skia on Linux, allowing a single code path for application developers.

Status and usage: As of its latest proposals, RanGDI remains an early-stage project with active discussion but limited production deployments. It is primarily of interest to maintainers of cross-platform GUI toolkits and teams porting legacy Windows applications, who seek to reduce per-platform code while maintaining familiar GDI semantics.