The vanilla adjective appears in many places: plain-vanilla java, vanilla javascript: what does it exactly mean?
From context, is seems to stand for something "plain".
When is a specific code considered vanilla and when is it not? Plain, like not wrapped in a framework?
Computer software, and sometimes also other computing-related systems like computer hardware or algorithms, is called Vanilla when not customized from its original form, meaning that it is used without any customizations or updates applied to it.