BASIC

Beginner's All-purpose Symbolic Instruction Code first ran on 1 May 1964 at Dartmouth College. John Kemeny and Thomas Kurtz wanted every student, not just the engineers, to be able to use the college computer, so the language got English keywords, line numbers and immediate feedback through time-sharing. 10 PRINT, 20 GOTO 10.

Its spread came with microcomputers. Microsoft's very first product was Altair BASIC (1975), and for the next decade nearly every home computer booted straight into a BASIC prompt — which made programming the first thing you saw rather than something you installed. Academia was less charmed: Edsger Dijkstra held that students exposed to BASIC were "mentally mutilated beyond hope of regeneration".