OpenSheetMusicDisplay (OSMD) is a TypeScript library for rendering MusicXML sheet music in web browsers. It parses MusicXML files, builds an internal musical data model, and renders it to SVG or Canvas using a heavily customized fork of VexFlow. It is the de facto standard open-source library for this specific task in the JavaScript ecosystem, supporting an interactive cursor, transposition, braille music output, and a wide range of MusicXML features (slurs, ties, dynamics, tablature, percussion, repeats, etc.). The codebase is notable for its extensive test suite covering hundreds of edge cases in music engraving. The architecture follows a strict pipeline: MusicXML parsing (MusicSheetReader) -> Internal Model (MusicSheet, VoiceData) -> Layout Calculation (VexFlowMusicSheetCalculator, SkyBottomLineCalculator) -> Rendering (VexFlowMusicSheetDrawer, SvgVexFlowBackend). The primary strength is its unmatched domain coverage for MusicXML rendering in the browser. The primary weakness is its tight coupling to a vendored and heavily patched fork of VexFlow (src/VexFlowPatch/), which creates significant technical debt and makes upgrading the rendering engine difficult. The codebase shows signs of organic growth with a large central configuration object (EngravingRules) and some brittle pixel-based tests.