Microsoft's own download page makes you pass a browser check first, and most third-party ISO sites bundle ads or unwanted installers. MSDL replicates Microsoft's own session flow to hand you the exact same signed CDN link, directly — no account, no ads, no browser gate. It ships two ways: a web app for quick lookups and a CLI (msdl) that runs the fetch from your own machine — useful since Microsoft rate-limits server-side traffic. Fully open source, self-hostable, no account or ads either way.