APSE standing for Ada Programming Support Environment was a specification for a programming environment to support software development in the Ada programming language. This represented the second stage of the U.S. military Ada project; once the language was implemented, it was felt necessary to specify and implement a standard set of tools, hence the APSE. CAIS-A, Common APSE Interface Set A, was defined in MIL STD-1838A.
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APSE Wikipedia(Text) CC BY-SA