+ \item $1946$: plankalk"ul - high-level programming language
+ \item $1950$: assembler - translating instruction mnemonics
+ \item $1954$: fortran - {\scriptsize formula translation}
+ \item $1963$: basic - {\scriptsize beginner's all purpose symbolic instruction code}
+ \item $1964$: os/360 - batch processing operating system
+ \item $1969$: unix - multics port to pdp-8, pdp-11/20
+ \item $1972$: c programming language - thompson, ritchie
+ \item $1978/84/85$: apple os/atari, amiga os/mac os
+ \item $1981/85/92/95$: ms-dos/windows 1.0/3.x/95
+ \item $1983$: gnu project - unix-like free software development
+ \item $1991$: linux - open-source kernel