Developer here who has been programming over 40 years (since I was a teenager in the late 1970s).
I know I am stretching things a bit here, but IBM mainframes, multi-user Forth systems, and distributed QNX systems ranging from the 1970s to the 1980s -- not to mention UNIX systems -- could all support remote procedure calls or interprocess/interapplication scripting across standard APIs to some extent (for a loose sense of process or application, especially with Forth). Even Smalltalk back then could do that to an extent but mostly from a single-user perspective in the sense that Smalltalk is mostly about message-passing objects. Essentially, you could have a system that could talk to itself or other similar systems in standard ways.
Yeah, there have been so many cycles of forgetting and reinventing with new generations of programmers. Although it is true some things improve even as sometimes other things decay for a constantly changing kaleidoscope of opportunities and risks (a bit like host/parasite arms races in evolutionary cycles).
https://en.wikipedia.org/wiki/History_of_CP/CMS
https://www.forth.com/resources/forth-programming-language/
https://en.wikipedia.org/wiki/QNX
https://www.qnx.com/developers/docs/qnx_4.25_docs/tcpip50/pr...
And also from the 1960s-1970s:
https://en.wikipedia.org/wiki/PLATO_%28computer_system%29
"Although PLATO was designed for computer-based education, perhaps its most enduring legacy is its place in the origins of online community. This was made possible by PLATO's groundbreaking communication and interface capabilities, features whose significance is only lately being recognized by computer historians. PLATO Notes, created by David R. Woolley in 1973, was among the world's first online message boards, and years later became the direct progenitor of Lotus Notes."
And from a different perspective, what is email but a standard way to do a remote procedure call to hopefully invoke some behavior -- even if a human may often be in the loop?
https://en.wikipedia.org/wiki/History_of_email
And from the 1930s an earlier Paul Otlet invented the idea of using a standard 3x5 index card to store and transmit information (mainly metadata):
https://en.wikipedia.org/wiki/Paul_Otlet
"Otlet was responsible for the development of an early information retrieval tool, the "Repertoire Bibliographique Universel" (RBU) which utilized 3x5 inch index cards, used commonly in library catalogs around the world (now largely displaced by the advent of the online public access catalog (OPAC)). Otlet wrote numerous essays on how to collect and organize the world's knowledge, culminating in two books, the Traité de Documentation (1934) and Monde: Essai d'universalisme (1935)."
For another example of cycles, my current favorite UI technology is Mithril+HyperScript+Tachyons for JavaScript (although Elm is great too conceptually, and likely inspired Mithril and React in part) which is so easy to use from a developer ergonomic point of view in part by (simplifying with a very broad brush) re-inventing the OpenGL video game paradigm of redrawing everything (with behind-the-scenes VDOM optimizations) from essentially a global state tree whenever the UI is considered "dirty" because someone touched it. Mithril is so much easier to use than UI systems that are all about creating dependencies (like most Smalltalk systems) or which require storing and updating state in carefully managed components (like React) or similar constrained models. But sadly React+JSX+SCSS has so far won the mindshare war despite overall worse developer ergonomics. I hope that cycle continues to turn someday and the Mithril approach will win out (if maybe in some other implementation by then).
https://github.com/pdfernhout/choose-mithril
Frankly it has been frustrating over the decades to see great ideas lose out for a time to lesser ones with better marketing or other institutional advantages or other non-technical issues (Forth vs. DOS, CPM vs. DOS, Smalltalk vs. Java, Mithril vs. React) or which better fit with the familiarity of developers with earlier systems (HyperScript vs. JSX, Lisp vs. C++). Yet, I can also still be hopeful things may improve as social dynamics and technical dynamics change over time in various ways. Like was said about JavaScript which I mainly program in now: "It is better than we deserve..."