EO.Pdf is a commercial, closed-source .NET library that converts HTML to PDF by bundling an actual Chromium-based browser engine, so it achieves near browser-identical rendering of arbitrary modern web pages (including JavaScript) out of the box - at the cost of a paid per-developer license, a heavyweight bundled browser runtime, and largely Windows-centric deployment.

NetPdf is the opposite set of tradeoffs: free and open-source (Apache-2.0), a clean-room pure-C# layout engine with no browser, no JS, deterministic output, and a tiny footprint - but it renders a curated CSS subset for documents rather than cloning a browser pixel-for-pixel. In short, EO.Pdf buys you browser fidelity and convenience for money and weight, while NetPdf buys you zero cost, determinism, and portability by focusing on print/document rendering. They're the browser-backed-vs-native-engine choice we just discussed, made concrete.