The language's designers realized that compiler testing is critical to Ada's success. Testing compilers for translating "proper Ada" actually predates the first Ada standard of 1983. The designers intended the language, initially used in large embedded systems, to be dependable, reusable, portable, maintainable, and legible. Many different programmers working toward the same goal had to simultaneously write, reuse, and integrate software components. After being fielded, the systems were assumed to have a long life during which they would port to many different hardware systems.

Ada 95 continues this emphasis on high reliability. The language is used for most modern aircraft fly-by-wire controls and new air traffic control systems, as well as rail transportation systems and satellites. Ada has been used in the Chunnel and the subway systems in Paris, Hong Kong, London, and New York; for manufacturing Volvos in Sweden; and for controlling steel mills in West Virginia. The language is used for smaller applications, such as network switching systems and e-commerce applications, where adaptability and time to market are important factors.

To realize its purpose, Ada must execute reliably across platforms and national borders. In other words, it must be standardized.

If Ada compilers translated dialects, not only would safety-critical verification of the software be difficult, but also the software would not be reusable, universally legible, or as maintainable. Today, the Ada Conformity Assessment Authority (ACAA) safeguards the procedures for testing Ada compilers' translations against the ISO standard.

Click here to read the full text of An ISO Standard Guards the Ada Hen House.