This book is aimed at both reviewing current Ada-based technology and appraising the 9X process. It contains some eleven technical papers which are extended versions of talks given during the 1991 International Ada UK conference. This conference took as its main theme the Ada 9X activity. Topics covered include CIFO (the catalogue of run-time features and options), proposed 9X mappings, asynchronous transfer of control in the tasking model, the design method HOOD and proposed extensions for hard real-time systems, applicable formal methods (LOTUS and Z), secondary bindings (including POSIX), multi-transputer applications, and recent initiatives of the AJPO. The authors are drawn from Europe and the US, and from industry, government agencies and academia. They include the Chair of ARTEWG, and Ada 9X distinguished reviewer, a member of the Ada 9X mapping team, and the director of the AJPO. The book's contents should be of interest to anyone concerned with Ada based technology. An introduction to the Ada 9X activity is given, but also included are details of the current proposals. In addition to the papers directly addressing Ada 9X, others cover a range of Ada related issues.