This volume contains the proceedings of the twelfthAda-Europe conference, held in France in 1993. The Frenchname "Ada sans fronti res" (the only French words in thebook) symbolizes the unlimitedness and novelty of Ada, aswell as Europe-wide interest.Many papers relate to Ada-9X, the new standard that the Adacoimmunity is close to achieving after worldwideconsultation and debate about requirements, specification,anddetailed definition. Their focus is on management,real-time, and compiler validation.Part of the conference was on object orientation, togetherwith various issues relating to the general structure of thelanguage, including exceptions to a certain use ofgenericity and heterogeneous data, efficiency, formalrequirements and CASEs, and comparison with a competitorlanguage.A third part relates to real-time, past with performancemeasurement, present with certification andapplications,and future with the ExTRA project and 9X.