Ada 2012 and Rationale
Documents for the third edition of the Ada Standard (usually known as Ada 2012), including the revised Ada Reference Manual and the Rationale for Ada 2012.
Ada 2005 (Ada 95 Amendment 1) and Rationale
Documents for Amendment 1 to Ada 95, including the consolidated Reference Manual (provided courtesy of Ada-Europe), and the Rationale for Ada 2005.
The 1995 Ada Standard Language Reference Manual, Rationale, Style-Guide, and other documents.
The 1983 Ada Standard Language Reference Manual, Rationale, Style-Guide, comments, and issues.
The Ada Semantic Interface Specification (ASIS) Standard has been published by the International Organization for Standardization (ISO) — 1999.
Military Standard 498
A copy MIL-STD-498 and its 22 Data item Descriptions (DIDs).
Ada Rapporteur Group
The Ada Rapporteur Group is the sub-sub-subcommittee directly responsible for maintaining the Ada Standard, including determining corrections and enhancements as needed. This site includes access to working documents and historical information.
Ada Conformity Assessment Authority
The Ada Conformity Assessment Authority is responsible for conformity assessment of Ada implementations, including setting testing policies, resolving disputes, and maintaining and enhancing the ACATS (the Ada Conformity Assessment Test Suite). The ACATS itself, updates, policies, and more can be found here.