Lisp is the easiest classic example that took ages to settle on a module standard and has had different competing standards over the years. PHP and Perl are pr

Lisp is the easiest classic example that took ages to settle on a module standard and has had different competing standards over the years. PHP and Perl are probably more recent examples comparable to JS here that provided mostly only low level plumbing (include/require) support and nearly wound up with multiple incompatible module loading patterns. Even C/C++ the "module" system started as a text processing hack in a macro pre-processor that used to be a separate tool (though I don't think any modern C/C++ toolchain uses a separate macro pre-processor, as there are tons of optimization layers now and some of the macro pre-processor knowledge makes its way all the way through to the linker these days). Historically, modules were always just "smash these two files together in this order" and it was only later that languages started asking hard questions such as "which symbols from this other file are available". The modern concept of modules as a fixed "shape" of self-describing public symbols is as much a later abstraction out of Object-Oriented Programming as anything else. Our idea of what a module should be in 2020 is much more informed by "recent" notions such as Component systems like COM and languages such as Java and C#.