I might be sounding a bit futuristic, but I think reference implementations should be auto-generated from a "spec" lang.
I don't know if a language for doing something like that even exists. Does anyone know of something like this?
EDIT: I should clarify: a spec should be _high-level_, i.e. abstract away all the unimportant details. Perhaps unit tests would be better in this case. Perl 6 follows this model.
But it would be even better if one could some how "fill in the details" of the specs separately, from the spec, rather than mesh the whole thing into one giant C puddle.
Not that they haven't gotten better. My point is that CPython has a different set of goals which makes it great for a reference implementation.