TrafficMonitor is a Windows desktop application written in C++ with MFC that provides real-time monitoring of network traffic (upload/download speed), CPU/memory usage, GPU/disk utilization, and hardware temperatures (CPU, GPU, HDD, motherboard). It features a floating main window and a taskbar-embedded window, both highly customizable through a skin system (INI/XML layouts with PNG/BMP backgrounds) and per-item color/font settings. The application integrates deeply with Windows: it can embed into the taskbar (supporting classical, Win11, and Wine variants), display a notification area icon, auto-start via registry or Task Scheduler, and adapt to dark/light themes and DPI scaling across multiple monitors. Architecturally, the codebase is organized around a central application class (CTrafficMonitorApp) that manages configuration, plugins, hardware monitoring, and UI windows. The UI is built with MFC dialogs (CTrafficMonitorDlg for main window, CTaskBarDlg and its subclasses for taskbar windows) and a tabbed options dialog (COptionsDlg) with pages for main window, taskbar, general, and display text settings. Rendering is abstracted through an IDrawCommon interface with multiple backends: GDI, GDI+, Direct2D (D2D1), DirectComposition, DXGI swap chains, and Direct3D 10.1 shaders, selected via a factory pattern. Hardware monitoring uses PDH performance counters (CPU, GPU, disk) and an optional LibreHardwareMonitor wrapper (C# interop) for temperatures. The plugin system loads DLLs implementing ITMPlugin/IPluginItem interfaces, allowing third-party display items, commands, and custom drawing. Key data flows include: periodic polling of network adapter statistics (via GetIfTable), PDH counters, and LibreHardwareMonitor sensors; storing daily traffic history in a local file with backup/recovery; and updating UI windows via timers and message passing. Configuration is persisted in INI files (config.ini, global_cfg.ini, skin.ini) with support for portable mode. The application also includes crash reporting (minidump generation with stack traces), update checking against GitHub/Gitee releases, and a comprehensive localization system using external INI language files (13+ languages). External dependencies include MFC, Windows SDK, tinyxml2 (bundled), OpenHardwareMonitorApi (bundled DLL), and optionally LibreHardwareMonitor for temperature monitoring.