Published in July, 2017, ISO 32000-2 is the first PDF specification developed within the ISO working-group structure. It enhances the "recipe" for PDF in several ways, including clarifications, new and improved features, various deprecations, and much more.
PDF 2.0 is the culmination of nine years of work by a dedicated group of approximately 30 subject-matter experts from around the world. Not a replacement to PDF 1.7, PDF 2.0 is a refinement of the venerable PDF format, originally published and made freely available by Adobe Systems since 1993.
One major difference as compared with previous versions of PDF; since ISO holds the copyright PDF 2.0 is not freely downloadable.
Unlike previous PDF specifications, however, PDF 2.0 is an open standard. Any subject-matter expert whose country is a member of ISO’s TC 171 SC 2 can join the other experts at the table, and help determine the nature and direction of the world’s de facto electronic document format.
The PDF Association maintains a set of historical reference files, originally published by Adobe Systems, that are used as normative references (and thus necessary to complete implementation) in ISO 32000-2. These documents are freely downloadable.