MediaPipe is a cross-platform framework for building multimodal machine learning pipelines, primarily targeting on-device inference. It provides a graph-based execution model where modular 'calculators' process typed 'packets' through directed acyclic graphs. The framework includes a rich library of pre-built calculators for image processing, tensor manipulation, audio analysis, and ML inference, as well as high-level task APIs for vision (face/hand/pose landmarking, image classification, segmentation), text (classification, language detection), audio (classification), and generative AI (LLM inference). The architecture is layered: a core C++ framework (mediapipe/framework/) defines the graph runtime, stream handlers, and packet infrastructure; a calculator library (mediapipe/calculators/) provides reusable processing nodes; and task-specific APIs (mediapipe/tasks/) offer consistent interfaces across C++, Java, Python, iOS, Web, and C. The system relies on TensorFlow Lite (LiteRT) for model execution, OpenCV for image operations, protobuf for configuration, and Abseil for utilities. Key entry points include the Python package (mediapipe/__init__.py), the C++ task APIs (mediapipe/tasks/cc/), and the web TypeScript modules (mediapipe/web/). The codebase is large and actively developed, with ongoing migration from older API patterns to newer ones (api2/api3), and some deprecated components (legacy Python solutions, older calculator interfaces).
Wox is a cross-platform desktop launcher (macOS, Linux, Windows) written in Go with a custom retained-mode UI framework. It provides a keyboard-first search interface with an extensive plugin system (system plugins in Go, external plugins via WebSocket hosts for Python and Node.js). Core features include file search with content indexing (SQLite FTS5, USN journal, FSEvents), clipboard history, calculator, converter, emoji picker, screenshot with annotation, window management, AI chat with multiple providers (OpenAI, Ollama, etc.), cloud sync with encryption, and system commands (shell, timer, dictation). The architecture is a monolith with a plugin manager dispatching queries to registered plugins, rendering results in a custom widget tree with GPU-accelerated painting. It has a sophisticated settings system with typed definitions, migrations, and cloud sync. The codebase is large but well-organized, with extensive platform-specific code for Windows (COM, Win32), macOS (AppKit, Objective-C), and Linux (GTK, Wayland, X11).
Nodify is a production-grade WPF library for building node-based graph editors. It provides a comprehensive set of custom controls (NodifyEditor, ItemContainer, Connector, various connection types, Minimap, GroupingNode, StateNode, etc.) along with a sophisticated input processing system based on composable state machines. The library is designed for MVVM, exposes rich command and event hooks, and supports full theming with dark/light/Nodify themes. The codebase demonstrates high craftsmanship in its input state machine pattern (InputProcessor/InputElementStateStack), undo/redo framework (ActionsHistory), gesture customization system (EditorGestures), and performance optimizations (BoxValue, connector safe-zone hit-testing). It ships with five example applications (Calculator, Playground, Shapes, StateMachine, Workflow) that showcase real-world usage patterns including sub-workflows, real-time collaboration simulation, and undo/redo. The library targets a wide range of .NET frameworks from .NET Framework 4.7.2 through .NET 10 preview, with CI builds and NuGet publishing pipelines. Despite a large API surface and some mutable global settings, the code is well-organized, extensively documented, and actively maintained.
This is Microsoft's open-source Windows Calculator, the production calculator app shipped on Windows. The repository is a full UWP/XAML application with Standard, Scientific, Programmer, Date, Unit Converter, and Graphing modes. The core is split into `CalcManager` (a native C++ calculation engine implementing arbitrary-precision rational arithmetic via the Ratpack library), `CalcViewModel` (C++/CX view models handling history, memory, copy/paste, unit data, navigation, and state snapshots), `Calculator` (the C#/XAML UI shell), and `GraphControl` (a DirectX-based graphing control). The app is MVVM-structured, heavily localized in 25+ languages, and includes both C++ unit tests and WinAppDriver-based UI tests.
Kalker is a multi-platform mathematical calculator implemented primarily in Rust. It provides a CLI with a REPL, a web component compiled to WebAssembly, and an Android mobile app via Capacitor. The core library (`kalk`) supports user-defined variables and functions, units, differentiation, integration, root finding, equation systems, matrices/vectors, complex numbers, and multiple number bases. The codebase is well-structured with a clear separation between parsing (lexer/parser), evaluation (interpreter), and a custom value system. It features extensive test files and integration tests for numerical methods. While the core numerical routines (tanh-sinh quadrature, Newton's method, Gaussian elimination) are tightly coupled to the interpreter, they are implemented with care and demonstrate non-trivial numerical analysis. The repository also includes build scripts for multiple targets and CI/CD pipelines.