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.
This repository is being used to work on an Editors Draft, and also for discussion and update of technical changes or additions.
A First Public Working Draft of the Third Edition of PNG was published in October 2022. (Changes from Second Edition) and updated on 20 July 2023 (changes since FPWD.
PNG Third Edition became a Candidate Recommendation on 21 September 2023 (Changes since previous publication)
There is an Explainer for features new in the Third Edition, and an Implementation Report.
The PNG Extensions specification is also here.