Adaptable Peripatetic Inquisitor

April 17, 2015 11:06 AM

What is the origin of the term API (Application Programming Interface)? Who coined it? What terms did it compete with?
posted by michaelh to Technology (6 answers total)

I always assumed it was an IBM term. It certainly sounds like one. In the sixties, both OS/360 and DOS/360 had application programming interfaces (incompatible, of course), and one of the advantages ascribed to the system was the modularity and portability that the API brought. I can honestly say that was the first time I ever heard of an API, but I have to admit that's because I don't go back any further than that.
posted by ubiquity at 11:37 AM on April 17, 2015 [2 favorites]

This Quora answer claims

It's history goes back to the first subroutine... the methods and scope of the calls and such have changed but not the concept.. the first modern API was HTTP and all modern API's justr expand on it.

Searching for more history gets mucked up with history of web APIs, which started on February 7th, 2000, when Salesforce.com officially launched their APIs at the IDG Demo 2000 conference.
posted by filthy light thief at 11:39 AM on April 17, 2015

I don't know where it *originally* came from, but (since I am old), I saw 'API' used a lot early in Win32 and COM - usually to describe the collective set of functions and types (concrete and abstract) used to customize or interact with a specific application suite (e.g. OLE types used in Office, Win32 types used to interact with NT Auth, etc). In fact, MSDN called it 'The Win32 API' even in the early 90s.

At the very least, at it's inception, the term had nothing to do with the web, and everything to do with documenting an externally callable set of automation.

I can also tell you that today it means "giant fucking collection of public entry points into giant fucking blocks of bad procedural code." maybe additionally it means "function signatures in our rad new disruptive javascript framework".

fwiw
posted by j_curiouser at 11:50 AM on April 17, 2015 [3 favorites]

Google Ngram Viewer says that the first usages of "application program interface" were in 1964 or thereabouts. (Note that if you search for "API" you get a lot more results, but I think most of them are not relevant.)

The first mention—excluding a couple of bogus hits (e.g. stuff "dated" erroneously from the 30s but containing much newer information)—is from the AFIPS Proceedings, Volume 33, Part 1, page 535. Only a small snippet is available via Google, unfortunately, and I don't have access to the full text. Perhaps someone else does.

Interestingly though, at least in the brief snippet, the author doesn't take the opportunity to introduce the initialism "API" for "application program interface", so it might not be the first usage of that particular abbreviated term, if indeed it is the first usage of "application program interface" at all.
posted by Kadin2048 at 11:42 PM on April 17, 2015 [1 favorite]

In 1983 Macintosh programming on the Lisa was based on the Macintosh application programming interface (API) called at that time the Macintosh Toolbox and Operating System routines.
I think the term API was popularised by the success of the MS-DOS API
posted by Lanark at 4:29 AM on April 18, 2015 [1 favorite]

Response by poster: Good leads here. I'm still looking for the One True™ origin if anyone happens to read this. Feel free to memail if the question becomes closed to new comments.
posted by michaelh at 10:34 PM on July 19, 2015