[toolslive]

Well, the original comment was implying org mode had limited popularity because there is no specification. I'm claiming cpython is way more popular compared to fe pypy because it has no spec. The typical scenario is: people try pypy. it mostly works but because of some weird problem some library is broken and then they give up.

[Groxx]

Is the claim that pypy has no spec, but cpython does? By that definition I think either both have a spec (they both use https://docs.python.org/3/reference/index.html and both are just "an implementation") or neither has one (since neither fully specifies all behavior and all modules, which is probably true for ~all languages).

[toolslive]

No. The claim is cpython has no spec. The link you posted is about the language. The spec claim is about the behaviour of the runtime.

The underlying claim is hat pypy cannot succeed precisely because there's no clear definition of success/compatibility/compliance. The situation is completely different in the Java world. There there is a specification for the memory model, runtime, aso and you can be sure that when you switch between runtimes, it will just work.