The Code is written by an editorial committee of Commissioners. Drafts of each section are made available for public comment before the final text is drafted. There is an Editorial Committee currently developing a new, 5th Edition of the Code. Input is sought via a wiki at: http://iczn.ansp.org/, or issues can be discussed on the ICZN listserver.
The Code is published by the International Trust for Zoological Nomenclature, http://www.iczn.org/The_Trust.htm, which thus holds the copyright. The Trust (ITZN) is a not-for-profit scientific charity that is supported by institutional subscriptions, donations, and grants. Copies of the Code are available for purchase from the ICZN Secretariat.