Long-running protocol systems have survived multi-decade horizons without organizational continuity

Four production protocols demonstrate the architectural pattern at planetary scale, each with multi-decade operational history and no single organization underwriting their continuity:

• DNS — 43 years (since 1983); 350 million registered domains; trillions of queries per day; never gone down globally (S-0016).
• Email (SMTP) — 44 years (RFC 821 1982; RFC 5321 2008); 4.73 billion active users; 392.5 billion messages per day in 2026 (S-0017, S-0018).
• BitTorrent — 25 years; over 2 billion cumulative installations of BitTorrent and µTorrent clients (S-0019); the Internet Archive uses BitTorrent for over 1 million items and describes it as "the now fastest way to download items from the Archive" (S-0020).
• Git — 21 years (initial commit April 7, 2005); 93.87% adoption among professional developers in 2024 (S-0021, S-0022).

The systems were designed under different threat models, by different communities, in different decades. They share the architectural pattern in M-0002: distribution across independent failure domains, verifiable integrity (where applicable), and persistence independent of any single organization. They are the empirical demonstration that Tier 3 architecture is not theoretical — it is the foundation of the open Internet and has been for decades.