NDlib is a Python library for modeling and simulating diffusion processes on complex networks, with a strong focus on epidemic compartment models and opinion dynamics. It provides a collection of built-in models (SIR, SEIR, voter model, bounded confidence, etc.), a flexible compartment-based composition system for building custom models, and a domain-specific language (NDQL) for defining models declaratively. The library also includes an interactive dashboard server for code-free experimentation, visualization modules (matplotlib and bokeh), and a sensitivity analysis runner via SALib. While the codebase demonstrates solid architectural patterns such as abstract base classes, configuration objects, and block schema registries, it suffers from significant technical drift: it retains Python 2 compatibility shims (six, future), uses outdated dependency versions, and has brittle test infrastructure. The dashboard and parser rely on dynamic code generation that is fragile. Overall, NDlib is a functional research-oriented library with reusable compartment and configuration patterns, but its maintenance has stalled, making it risky for new projects without substantial modernization.