Hello Decimal World
js> print(new Decimal("8.5"));
8.5
OK, so it is not much yet. But it is a constructor, a toString method, and a finalizer. And it makes use of decQuadFromString and decQuadToString from the decNumber library. And it is in the context of a real codebase, namely SpiderMonkey, which is what Firefox uses. And it is in a public repository that you can clone, pull, and download from; and perhaps even try building yourself or patching.