HandBrake is a cross-platform video transcoder application with GUIs for macOS (Cocoa/Objective-C), Windows (WPF/C#), and Linux (GTK/C). It features a shared core library (libhb) handling video/audio encoding, filtering, muxing, and job management. The application supports preset-based configuration, hardware acceleration (QSV, NVEnc, VCE, VideoToolbox), batch processing via job queues, and extensive format/subtitle handling. Architecture follows platform-appropriate patterns: MVVM in WPF, delegates/protocols in macOS, and GObject-based design in GTK. The codebase demonstrates strong modularity, clear separation of concerns, and active maintenance across all platforms.