This repository is for the maintenance of the PNG specification, the Second Edition of which was jointly published in 2003 by W3C as a W3C Recommendation, and by ISO as an International Standard ISO/IEC 15948:2003 (E) with identical contents. The Third Edition was published as a W3C Recommendation on 24 June 2025.
This repository is being used to work on an Editors Draft of the Fourth Edition.
The PNG Extensions specification is also here.