An updated edition of the Ada 2012 Rationale is available at:http://www.ada-auth.org/standards/rationale12.html
This edition of the Rationale combines the first six chapters of the Rationale into a single document, fixes a number of errors, adds an index, and adds discussion of various details of Ada 2012 that were changed since the original publication of these chapters in the Ada User Journal. Newly added material includes discussions of new features related to iterators and storage pools. We expect that additional chapters will be added to this edition roughly every three months.
The Rationale for Ada 2012 provides an overview of new Ada 2012 features, examples of their use, compatibility with Ada 95 and 2005, and more. It was written by John Barnes, and was sponsored in part by the Ada Resource Association. This is an unofficial description of the language; refer to the Ada 2012 standard for detailed language rules.