nodemon is a CLI tool and library that monitors a directory for file changes and automatically restarts a specified command (typically a Node.js application). It parses command-line arguments and configuration files (nodemon.json, package.json) to determine watch paths, ignore patterns, file extensions, and the command to execute. It uses chokidar for file system watching and manages child processes via fork or spawn. When changes are detected, it matches the changed files against configured rules and restarts the child process if appropriate. It supports custom signals, delay, legacy polling, and event hooks. The architecture is monolithic with a library API, key modules include CLI parser, config loader, rule engine, file watcher, and process manager. The codebase relies on non-standard Node.js APIs (e.g., process.stdin.setEncoding, child_process.fork, process.versions.node), indicating significant technical drift from standard Node.js, though the tool remains widely used and actively maintained.

jsconsole is a web-based JavaScript REPL and remote debugging tool. The frontend is a React (Preact-compat) single-page application with Redux state management, allowing users to type and execute JavaScript commands in a sandboxed iframe. Results are rendered with a rich type-aware display that supports expand/collapse for objects, arrays, functions, promises, and more. The backend is a Node.js/Express server that serves the static build and provides real-time communication via Server-Sent Events (SSE) for remote debugging sessions. Users can start a remote session (listen) to bridge console.log calls from another browser or device back to the main console, and also inject commands remotely. Architecturally, the codebase follows a standard client-server model with a React SPA. It makes clever use of AST parsing (via Babylon) in the `preProcess` function to handle JavaScript declarations (const/let) and async/await in the REPL, transforming input so that eval returns the final expression value. The backend uses a lightweight custom SSE session manager (`lib/es.js`) that could be extracted for other real-time projects. However, the project is technically very dated, with React 15, Webpack 2, and many other dependencies from 2017-2018. Despite this, the core REPL logic and type-rendering components are well-architected and could serve as a reference implementation for similar tools.