[saurik]

The number of people who use those alternative implementations -- or even the quality of their output with respect to performance or platform support -- don't really matter: the reason to insist on (at least, and as unrelated as possible) two separate implementations of something is to ensure that the behavior of the language isn't merely an accident of incorrect code in the compiler instead of an intentional choice by the language designers, as it shows that two different teams came to the same result (at which point hopefully it is noticed if there are spec issues and those are either corrected in the parent compiler or "bug for bug" duplicated in the child compiler after documenting the issue in the spec). Until you have done this, it is difficult to even claim what the language even is.