c. 2500 BCE 2020s
Computing wasn't invented by one genius or one country. Follow twelve centuries of ideas, machines and programs, and meet the people who made them.
c. 2500 BCE
Counting boards with pebbles or beads let merchants add and subtract faster than writing. It is the first tool where the position of a marker gives it its value.
c. 300 BCE
Euclid describes a step-by-step method for finding the greatest common divisor of two numbers. It is one of the oldest algorithms still in daily use, inside every secure web connection.
c. 100 BCE
A box of at least thirty bronze gears that modelled the motions of the Sun and Moon and predicted eclipses. Nothing as intricate is known for the next thousand years.
c. 820
Al-Khwarizmi writes clear, general procedures for calculating with Indian numerals and for solving equations. Translated into Latin, his name becomes the word algorithm and his book's title gives us algebra.
c. 850
The three Banu Musa brothers describe an automatic flute player controlled by pegs on a rotating cylinder. Rearranging the pegs changes the tune: the earliest known machine with a stored, replaceable program.
c. 850
Al-Kindi explains how to read a secret message by counting how often each symbol appears and matching the counts to the letters of the language. Frequency analysis is the first algorithm of cryptanalysis.
1206
Al-Jazari's book describes some fifty machines in enough detail to rebuild them, including a boat of mechanical musicians whose rhythms are set by movable pegs, and the crankshaft.
1642
Aged 19, Blaise Pascal builds a machine of geared wheels that adds and carries automatically, to help his father with tax accounts.
1703
Leibniz publishes his explanation of arithmetic using only 0 and 1, and notes how simple its rules are for a machine.
1804
A chain of punched cards tells a loom which threads to lift, row by row. A portrait of Jacquard woven in silk needed 24 000 cards.
1843
Ada Lovelace's notes on Babbage's Analytical Engine include a complete program for calculating Bernoulli numbers, with a loop, and the idea that such a machine could handle music and symbols as well as numbers.
1854
George Boole shows that reasoning can be calculated with just two values, true and false, and three operations: AND, OR and NOT.
1890
Herman Hollerith's electric tabulating machines process the US census from punched cards. Data processing becomes an industry, and his firm later becomes part of IBM.
1936
Alan Turing defines computation with an imaginary machine of tape and rules, shows that one machine can imitate all others, and proves that some problems can never be solved by any program.
1937
Claude Shannon's master's thesis proves that circuits of switches obey Boole's algebra, so any logical or arithmetic operation can be built from them.
1941
Konrad Zuse completes the first working programmable, fully automatic computer, using binary arithmetic and 2 600 relays, with programs on punched film.
1945
The first large general-purpose electronic computer: about 18 000 vacuum tubes, 27 tonnes, a thousand times faster than relay machines. It is programmed by six women, with cables and switches.
1947
Bardeen and Brattain make a solid crystal amplify a signal, and Shockley soon designs a sturdier version. The vacuum tube now has a replacement that is small, cool and reliable.
1948
The Manchester "Baby" runs a 17-instruction program held in its own memory. From now on, changing what a computer does means loading new numbers, not rewiring it.
1952
Grace Hopper's A-0 system assembles a program from a library of routines. She calls it a compiler, and argues that people should be able to program in words.
1957
The first widely used high-level language and optimising compiler. Scientists can write formulas, and the result runs nearly as fast as hand-written assembly.
1958โ1959
Jack Kilby and Robert Noyce independently build whole circuits on a single piece of semiconductor. Noyce's planar version can be mass-produced by printing.
1959
Mohamed Atalla and Dawon Kahng build the metalโoxideโsemiconductor transistor. Flat, simple to make and easy to shrink, it becomes the most manufactured device in history.
1965
Gordon Moore predicts that the number of components on a chip will keep doubling at a regular pace. The industry makes it come true for more than fifty years.
1969
The Apollo guidance computer, with about 4 kilobytes of working memory, survives an overload during the final descent because its software was designed to shed low-priority work.
1969
Two computers 560 km apart are linked by the ARPANET. The first message was meant to be LOGIN; the system crashed after LO. The network grows into the internet.
1971
The Intel 4004 packs a complete 4-bit processor, 2 300 transistors, onto a chip the size of a fingernail. It was designed for a Japanese desktop calculator.
1972
Dennis Ritchie creates the C language so that Ken Thompson's Unix operating system can be moved from one kind of computer to another. Both are still everywhere.
1975โ1981
The Altair kit, the Apple II and the IBM PC bring computers into homes and offices. Programming becomes a hobby, and software becomes an industry.
1985
IEEE 754 fixes how floating-point numbers are stored and rounded, so that the same calculation gives the same result on every machine.
1989โ1991
Tim Berners-Lee proposes linked pages on the internet, writes the first browser and server, and gives the design away. Within a decade the web reaches hundreds of millions of people.
1991
A student, Linus Torvalds, shares the kernel of a free operating system. The same year Guido van Rossum releases Python. Both are built in the open by volunteers around the world.
2007
The modern smartphone combines a fast processor, a touch screen, sensors and a permanent network connection. Within fifteen years most people on Earth carry one.
2012
A neural network trained on graphics processors wins an image-recognition contest by a wide margin. Programs that learn from examples, rather than following hand-written rules, spread into every field.
2020s
Large language models can draft working code from a description in ordinary words. The programmer's job shifts further towards stating the problem clearly and checking the result.
c. 780 โ c. 850
Khwarazm and Baghdad
Known for
Step-by-step methods for arithmetic with Indian numerals and for solving equations. The words algorithm and algebra both come from his work.
Fun fact
For centuries in Europe, "algorism" simply meant doing sums with the new digits instead of an abacus.
c. 801 โ c. 873
Kufa and Baghdad
Known for
The first written description of frequency analysis: breaking a cipher by counting how often each symbol occurs.
Fun fact
His manuscript on deciphering messages was lost for centuries and rediscovered in an Istanbul archive in 1987.
1136 โ 1206
Upper Mesopotamia
Known for
A book of some fifty machines with building instructions: clocks, pumps, automata and a band of mechanical musicians with re-arrangeable pegs.
Fun fact
His elephant clock combined ideas from India, China, Persia, Greece and Egypt on purpose, as a tribute to all of them.
1646 โ 1716
Germany
Known for
Binary arithmetic, and a calculating machine that could multiply and divide.
Fun fact
He dreamed of a machine that could settle any argument by calculation: "Let us calculate!"
1752 โ 1834
Lyon, France
Known for
A loom controlled by a chain of punched cards, so that any pattern could be woven by changing the cards.
Fun fact
Babbage owned a silk portrait of Jacquard woven from 24 000 cards and showed it to visitors to explain his own engine.
1791 โ 1871
London
Known for
The Analytical Engine: a design for a general-purpose mechanical computer with a processor, a memory and punched-card programs.
Fun fact
His simpler Difference Engine was finally built from his drawings in 1991. It works perfectly.
1815 โ 1852
London
Known for
The first published program, and the insight that a computing machine could work on any symbols, not only numbers.
Fun fact
She called her approach "poetical science". The programming language Ada is named after her.
1815 โ 1864
England and Ireland
Known for
Boolean algebra: logic written as calculation with true and false.
Fun fact
He left school at 16 to support his family and taught himself mathematics from library books.
1860 โ 1929
USA
Known for
Electric machines that counted and sorted data on punched cards, first used for the 1890 US census.
Fun fact
He got the idea from watching a train conductor punch tickets to record each passenger's description.
1912 โ 1954
England
Known for
The Turing machine, the universal machine, the halting problem, wartime code-breaking, and the first serious question about machine intelligence.
Fun fact
He was a long-distance runner good enough to try out for the 1948 Olympic marathon.
1910 โ 1995
Berlin
Known for
The Z3 (1941), the first working programmable, fully automatic computer, and Plankalkรผl, an early design for a high-level language.
Fun fact
He built his first computer, the Z1, in his parents' living room.
1916 โ 2001
USA
Known for
Showing that switch circuits can compute logic (1937), and founding information theory, which measures all information in bits (1948).
Fun fact
He rode a unicycle through the corridors of Bell Labs while juggling, and built a mechanical mouse that learned its way through a maze.
1903 โ 1957
Hungary and USA
Known for
The 1945 report describing the stored-program computer, whose layout of processor and shared memory still bears his name. Also merge sort.
Fun fact
He could divide eight-digit numbers in his head as a child and recite books he had read years before.
1945 โ 1946
Philadelphia
Known for
Kay McNulty, Betty Jennings, Betty Snyder, Marlyn Wescoff, Fran Bilas and Ruth Lichterman worked out how to program the first general-purpose electronic computer, with no manual and no language.
Fun fact
Their role was almost forgotten until the 1980s, when a student noticed unnamed women in old ENIAC photographs and went looking for them.
1906 โ 1992
USA
Known for
The first compiler (A-0, 1952) and the idea of programming in English-like words, which led to COBOL.
Fun fact
Her team once taped a moth found in a relay into the logbook: "first actual case of bug being found".
1947
Bell Labs, USA
Known for
The invention of the transistor, for which they shared the 1956 Nobel Prize in Physics.
Fun fact
John Bardeen later won a second Nobel Prize in Physics, for explaining superconductivity. He is the only person to have won it twice.
1959
Bell Labs, USA
Known for
The MOSFET, the transistor design used in virtually every chip. Atalla, born in Port Said, Egypt, also found how to tame the silicon surface so that it would work.
Fun fact
Atalla later founded a company for securing bank transactions; the PIN you type at a cash machine comes from his work.
1958 โ 1959
Texas and California
Known for
The integrated circuit: many components made together on one chip. Kilby showed it could be done; Noyce found the way to manufacture it.
Fun fact
Kilby built his first chip while his colleagues were on summer holiday: as a new employee he had no leave yet.
1929 โ 2023
California
Known for
Moore's law (1965), and co-founding Intel, which made the first microprocessor.
Fun fact
He said he could not bring himself to say "Moore's law" for about twenty years.
1924 โ 2007
IBM, USA
Known for
FORTRAN (1957), the first widely used high-level language, and a notation for describing the grammar of programming languages.
Fun fact
He said he invented FORTRAN because he was lazy and disliked writing programs.
1930 โ 2002
Netherlands
Known for
Structured programming, the run-time stack for recursion, and the shortest-path algorithm used by every map app.
Fun fact
He designed his shortest-path algorithm in twenty minutes at a cafรฉ table, without pencil or paper.
born 1936
MIT, USA
Known for
Leading the Apollo flight software and coining the term software engineering.
Fun fact
A famous photograph shows her standing beside the printed Apollo code. The stack is as tall as she is.
1969 โ 1973
Bell Labs, USA
Known for
The Unix operating system and the C language. Linux, macOS, Android and most of the internet descend from their work.
Fun fact
Thompson wrote the first version of Unix in about a month, while his wife and baby were away visiting family.
born 1933
Canada and Berkeley
Known for
The IEEE 754 standard for floating-point arithmetic, used by virtually every processor.
Fun fact
He is known for hunting down subtle arithmetic errors in calculators and chips, and for explaining them patiently to their makers.
born 1955
CERN, Geneva
Known for
The World Wide Web: web addresses, HTML and the first browser and server, released without patents or fees.
Fun fact
His boss wrote "Vague, but exciting" on the cover of his proposal.
born 1969
Helsinki
Known for
The Linux kernel (1991), built in the open by thousands of contributors, and Git, the tool programmers use to work on code together.
Fun fact
He announced Linux as "just a hobby, won't be big and professional".
born 1956
Amsterdam
Known for
The Python language (1991), designed to be easy to read, and now one of the most used languages in science, teaching and AI.
Fun fact
The Python community gave him the title "Benevolent Dictator For Life"; he stepped down from it in 2018.