Implementation Aspect

Niklaus Wirth, the designer of Pascal (and other languages since then), states that a "programming language is as good as its compiler". The first compilers for PL/1 were so buggy that the language's use was affected. When Ada was designed, the design team, remembering the problems with PL/1, designed validation requirements that a compiler would have to pass to be considered a legal Ada compiler.

The time to construct the compiler and its size and speed as well as its "user-friendliness" are all factors to be considered. The original FORTRAN compiler took 18 person-years to develop! We can now design and implement a compiler much faster because tools to generate various phases have been developed and becuase algorithms and data structures for the various compiler tasks have been developed.