No, the official name for io.js is io.js, it is explicitly not Io.js. You can tell because this is what the owners of the project have clearly stated. Linguistic rules (which are rarely in fact rules), have nothing to do with it. If I tell you my name is "bob" and not "Bob" then I'm right because it's my name, you don't get to enforce your own preferences, just because of the language you speak.