Lisp started out at the same time and represents a different family of languages.

In the 1960s there was a lot of work on languages like ALGOL and PL/I which were intended to occupy the niche that C occupied. One problem was that people didn’t know what I/O was going to look like and didn’t realize it didn’t matter for language design because you could relegate I/O to the standard library.

It was certainly one of the first, and for the most part I think it's generally regarded as the first "real" high level language. But there are a number of other languages that were developed at approximately the same time where you could probably quibble a bit about exactly which one came first. COBOL[1], for example, and some of the predecessors to COBOL, like FLOW-MATIC[2] and ARITH-MATIC[3]. Also, as PaulHoule mentions, there was LISP[4], and then there was IPL[5] which LISP descended from. COMIT[6] also dates back to that general era.

[1]: https://en.wikipedia.org/wiki/COBOL

[2]: https://en.wikipedia.org/wiki/FLOW-MATIC

[3]: https://en.wikipedia.org/wiki/ARITH-MATIC

[4]: https://en.wikipedia.org/wiki/Lisp_(programming_language)

[5]: https://en.wikipedia.org/wiki/Information_Processing_Languag...

[6]: https://en.wikipedia.org/wiki/COMIT

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