Software Heritage — 27B source files from 421M projects under content-addressed Merkle DAG; SWHID is ISO/IEC 18670

Software Heritage's Activity Report 2025 (January 2026) reports that the archive holds 27 billion unique source files from 421 million projects under a Merkle DAG content-addressed model. The Software Heritage Identifier (SWHID) was published as ISO/IEC 18670, an international standard.

For C-0009: Software Heritage is a production-scale operational demonstration of the three architectural principles (M-0002) — distribution across independent failure domains, verifiable integrity through content addressing, and a governance model that does not depend on any single organization's continuity (mirrors operate at Inria, ENS Paris-Saclay, and partner institutions globally).

For C-0014: SWHID's standardization as ISO/IEC 18670 establishes that content addressing operates on production source-code archives at billions-of-files scale, regardless of file format, language, or origin. The standardization removes a common objection ("content addressing is research-only") by demonstrating that the property holds in international-standards-track production deployment.