> Is there a requirement that compilers for these two languages be
> validated?  If so, who validates the C compilers?  It's my understanding
> that NIST is going out of the compiler validation business.  Surely you
> don't require that Ada compilers be validated while allowing unvalidated
> C compilers?

IMNSHO, validation was important to a VERY small subset of
developers/projects/program managers.  Many, many people have
overestimated the value of validation as a "motivator".  What we did
is create this type of logic (argue all you want, I've seen it
hundreds of times personally):

        if language = C then
                if vendor claims it complies with ANSI standard then
                        the compiler is good
                        it's probably even better with those extensions
                end if
                C is a good choice since everybody knows it
        end if

        if language = Ada then
                if compiler is unvalidated then
                        the compiler is very bad
                        compiler is very expensive
                end if
                don't use Ada
        end if