Computing History

Mechanical Precursors

• Abacus — counting frame used across ancient Mesopotamia, China, and Rome; no single inventor; still used in parts of East Asia as a calculation aid.
• Antikythera mechanism — Greek analog device (~100 BCE) for computing astronomical positions; considered the earliest known geared mechanism.
• Napier’s Bones — calculation aid invented by John Napier (1617); numbered rods that simplified multiplication and division; Napier also invented logarithms (1614), which made large multiplications reducible to addition.
• Slide rule — analog calculation device based on logarithmic scales; predecessor credited to William Oughtred (~1622); used by scientists and engineers until the 1970s when electronic calculators replaced it.
• Pascaline — mechanical adding machine built by Blaise Pascal (1642); performed addition and subtraction via interlocking gears; one of the first documented automatic calculators.
• Stepped Reckoner (Leibniz calculator) — designed by Gottfried Wilhelm Leibniz (~1672); could add, subtract, multiply, and divide using a stepped cylinder gear; Leibniz also developed the binary number system foundational to all digital computing.
• Jacquard loom — Joseph Marie Jacquard (1804); used punched cards to control weaving patterns; a direct conceptual ancestor of punched-card data input and programmable machines.
• Charles Babbage — designed the Difference Engine (1822, partial build) for tabulating polynomial functions; then the far more ambitious Analytical Engine (from 1837), which incorporated a mill (processor), store (memory), input via punched cards, and conditional branching. Never fully built in his lifetime.
• Ada Lovelace — mathematician who wrote extensive notes on Babbage’s Analytical Engine (~1843), including what is widely regarded as the first algorithm intended for machine execution; often cited as the first computer programmer. Her Note G describes an algorithm for computing Bernoulli numbers.
• Arithmometer — Thomas de Colmar (1820, commercialized 1851); the first mass-produced mechanical calculator; widely used in insurance and banking.
• Schickard’s calculating clock — Wilhelm Schickard’s mechanical calculator (~1623), described in letters to Kepler; sometimes cited as the earliest mechanical calculator predating Pascal, though no complete working original survives.
• Leibniz binary system — Gottfried Leibniz formalized the binary (base-2) numeral system and connected it to the Chinese I Ching in his 1703 paper; the binary system underlies all modern digital computing.
• Difference Engine No. 2 (completed) — the Science Museum London completed a working Difference Engine No. 2 from Babbage’s original plans in 1991, proving the design was mechanically sound.

Boolean Logic and Theoretical Foundations

• George Boole — published An Investigation of the Laws of Thought (1854); defined Boolean algebra (AND, OR, NOT operations on binary values 0/1), the logical backbone of digital circuits.
• Claude Shannon — MIT master’s thesis (1937) showed Boolean algebra could describe electrical switching circuits; established the theoretical link between binary logic and electronics. Later founded information theory with A Mathematical Theory of Communication (1948), introducing bit, entropy, and the noisy-channel coding theorem. The bit (binary digit) is the fundamental unit of information.
• Alan Turing — introduced the Turing machine (1936) as an abstract model of computation: a tape, a read/write head, and a finite set of rules. Proved some problems are undecidable (halting problem). Defined computational universality; a universal Turing machine can simulate any other. Proposed the Turing test (1950, “Computing Machinery and Intelligence”) as a criterion for machine intelligence.
• Alonzo Church — independently developed lambda calculus (1936) as an equivalent model of computation; the Church-Turing thesis holds that any effectively computable function can be computed by a Turing machine.
• Kurt Gödel — incompleteness theorems (1931) showed any sufficiently powerful formal system contains true statements it cannot prove; influenced Turing’s undecidability results.
• John von Neumann — the von Neumann architecture (described in the 1945 “First Draft of a Report on the EDVAC”) stores both program instructions and data in the same memory, allowing programs to modify themselves; the dominant CPU design model to this day. Also made foundational contributions to game theory, quantum mechanics, and the Manhattan Project.
• Norbert Wiener — founded cybernetics (1948, book Cybernetics: Or Control and Communication in the Animal and the Machine); studied feedback loops and control in biological and mechanical systems; coined the term “cybernetics” from the Greek for “steersman.”
• Konrad Zuse — German engineer who built the Z3 (1941), often cited as the first operational program-controlled electromechanical computer; used floating-point binary arithmetic. Largely developed in isolation during WWII. Also designed the Plankalkül programming language (~1945), often called the first high-level programming language though not implemented at the time. Earlier machines Z1 (1938, mechanical) and Z2 preceded the Z3.
• Tommy Flowers — British Post Office engineer who designed Colossus; his use of vacuum tubes in large numbers was considered reckless by contemporaries; after the war, secrecy prevented him from receiving full credit for decades.
• IAS machine — stored-program computer built at Princeton’s Institute for Advanced Study under von Neumann’s supervision (~1951); its detailed design was widely copied by universities and labs worldwide, making it the most influential early computer architecture after the Manchester Baby.
• Halting problem — Turing’s 1936 proof that no algorithm can determine, for all program-input pairs, whether the program halts; a landmark result in computability theory establishing fundamental limits of computation.
• P vs. NP problem — posed formally by Stephen Cook (1971) with his proof that SAT is NP-complete; asks whether every problem whose solution can be verified quickly can also be solved quickly; one of the seven Clay Millennium Prize Problems.
• NP-completeness — Cook’s theorem (1971) and Richard Karp’s 21 NP-complete problems (1972) established the theory of computational complexity classes; NP-complete problems include the Traveling Salesman Problem and Boolean satisfiability (SAT).
• Shannon’s noisy-channel coding theorem — a central result in information theory proving that data can be transmitted at rates up to the channel capacity with arbitrarily low error; underpins all modern error-correcting codes and digital communications.
• Turing Award — given annually by the ACM since 1966; often called the “Nobel Prize of Computing”; named for Alan Turing. First recipient: Alan Perlis (1966).

Hollerith, Punch Cards, and Early Tabulation

• Herman Hollerith — invented the electromechanical tabulating machine using punched cards for the 1890 U.S. Census; reduced tabulation time from ~8 years to ~1 year. He founded the Tabulating Machine Company (1896) which eventually became IBM. The unit of data storage “hollerith” carries his name in some early contexts.
• Tabulating Machine Company — founded by Hollerith (1896); merged into CTR (Computing-Tabulating-Recording Company, 1911), which was renamed IBM (International Business Machines) in 1924 under Thomas J. Watson Sr.
• IBM 80-column card — the dominant punched-card format for decades; the phrase “do not fold, spindle, or mutilate” became a cultural touchstone.
• Unit record equipment — punch-card-based machines (sorters, collators, tabulators) dominated business data processing from ~1900 through the 1950s.
• Thomas J. Watson Sr. — longtime CEO of IBM (1914–1956); built IBM into a dominant technology company; his motto “THINK” became IBM’s corporate slogan.
• Thomas J. Watson Jr. — son of Watson Sr.; oversaw IBM’s pivot to electronic computers (System/360 era); succeeded his father as CEO (1956–1971); regarded as the executive who made IBM dominant in the mainframe era.

WWII and Early Electronic Computers

• Colossus — built at Bletchley Park (UK, 1943–44) to break Lorenz cipher messages; designed by Tommy Flowers; used ~1,500–2,400 vacuum tubes; often called the first programmable electronic computer, though it was not general-purpose and was kept secret until the 1970s.
• Atanasoff-Berry Computer (ABC) — designed by John Atanasoff and Clifford Berry (Iowa State, ~1939–42); electronic, binary, special-purpose; did not store programs; a 1973 U.S. court ruling (Honeywell v. Sperry Rand) credited Atanasoff over Eckert and Mauchly for certain patent claims, invalidating the ENIAC patent.
• ENIAC — Electronic Numerical Integrator and Computer; built at the University of Pennsylvania by J. Presper Eckert and John Mauchly; operational 1945; ~18,000 vacuum tubes; originally programmed by physically rewiring patch cables. The six primary ENIAC programmers were women (Kay McNulty, Betty Jennings, Betty Snyder, Marlyn Wescoff, Fran Bilas, Ruth Lichterman).
• Harvard Mark I — electromechanical computer (IBM ASSC) completed 1944; designed by Howard Aiken; used at Harvard for ballistics calculations; Grace Hopper worked on it and famously documented a moth found in a relay as an early use of the word “bug” in computing.
• EDVAC and stored-program concept — von Neumann’s 1945 draft described a machine where both data and instructions live in memory; EDVAC (completed 1949) was one of the first stored-program computers.
• Manchester Baby (SSEM) — Small-Scale Experimental Machine, University of Manchester (June 1948); widely cited as the first stored-program computer to run a program. Freddie Williams and Tom Kilburn led its construction.
• Williams tube — cathode-ray-tube memory device developed by Freddie Williams at Manchester; used in the Manchester Baby as the first random-access electronic memory.
• EDSAC — Electronic Delay Storage Automatic Calculator; Maurice Wilkes, Cambridge (1949); another early stored-program computer; introduced the concept of subroutines.
• Bletchley Park — British codebreaking center during WWII; Turing worked there on Bombe machines to decrypt Enigma traffic. The Bombe was an electromechanical device that exploited cribs (known plaintext) to narrow the Enigma key space.
• Enigma machine — German electromechanical cipher device used throughout WWII; rotor-based substitution cipher broken by Polish mathematicians (Marian Rejewski et al.) before the war and then by the British at Bletchley Park.
• UNIVAC I — Universal Automatic Computer; first commercially sold computer in the U.S. (1951); built by Eckert and Mauchly (later acquired by Remington Rand); delivered to the U.S. Census Bureau; famously predicted Eisenhower’s victory in the 1952 presidential election on CBS television.
• Maurice Wilkes — British computer scientist at Cambridge who built the EDSAC (1949); inventor of microprogramming; first Turing Award recipient from the UK (1967); wrote the first practical book on programming (with Wheeler and Gill, 1951).
• Freddie Williams and Tom Kilburn — University of Manchester engineers who built the Manchester Baby (1948); Williams invented the Williams tube (CRT-based RAM); Kilburn later led the Atlas project.
• SAGE (Semi-Automatic Ground Environment) — U.S. Air Force air-defense network (1950s–60s); among the largest and most expensive computer systems ever built; pioneered real-time interactive computing and light-gun interfaces; directly funded early computer science research at MIT (Whirlwind project).
• Whirlwind — MIT real-time computer (Jay Forrester, 1951); developed magnetic core memory, which became the dominant RAM technology for two decades; precursor to SAGE.

Generations of Computing Hardware

First Generation: Vacuum Tubes (1940s–mid 1950s)

• Characteristics — vacuum tubes as switching elements; machine language programming; room-sized machines; high power consumption and heat; frequent tube failures.
• IBM 701 — IBM’s first commercial scientific computer (1952); leased to government and research customers; also called the “Defense Calculator.”
• Magnetic core memory — invented by Jay Forrester at MIT (~1949–51); arrays of tiny ferrite rings storing one bit each; dominated RAM technology from the mid-1950s through the early 1970s; “core” became a synonym for RAM.
• Drum memory — rotating magnetic drum used as primary memory in several 1950s computers (IBM 650); predecessor of the hard disk drive.

Second Generation: Transistors (mid 1950s–early 1960s)

• Transistor — invented at Bell Labs by John Bardeen, Walter Brattain, and William Shockley (December 1947); Nobel Prize in Physics 1956; smaller, faster, more reliable, and cooler than vacuum tubes. The point-contact transistor was the first type demonstrated; the more practical bipolar junction transistor followed.
• William Shockley — co-inventor of the transistor; founded Shockley Semiconductor (1956) in Mountain View, CA; his authoritarian management style drove eight engineers (the “Traitorous Eight,” including Kilby and Noyce) to leave and found Fairchild Semiconductor, seeding Silicon Valley.
• IBM 1401 — highly successful transistor-based business computer (1959); over 10,000 units sold; helped IBM dominate the mainframe market.
• IBM 7090/7094 — transistorized scientific mainframes (1959–62); used by NASA for early space missions; John Glenn’s orbital calculations famously required “the girl” Katherine Johnson to verify the IBM output before he would fly.
• FORTRAN — Formula Translation; first high-level compiled programming language, developed by IBM (John Backus team, 1957); designed for scientific computation; demonstrated that high-level languages need not sacrifice performance. Backus later invented Backus-Naur Form (BNF), the standard notation for describing programming language grammars.
• COBOL — Common Business-Oriented Language; developed with major contributions from Grace Hopper (1959–60); designed to read like English; still in heavy use in banking and government.
• Grace Hopper — U.S. Navy rear admiral and computer scientist; created the first compiler (the A-0 system, 1952), which translated symbolic mathematical code into machine code; championed human-readable programming languages; popularized the term “debugging.”
• LISP — List Processing language; designed by John McCarthy at MIT (~1958–60); the second oldest high-level language still in widespread use; based on lambda calculus; foundational in artificial intelligence research; introduced concepts such as garbage collection, higher-order functions, and dynamic typing.
• ALGOL — Algorithmic Language; international committee language (ALGOL 58, ALGOL 60); influenced virtually every subsequent procedural language; introduced block structure, recursion, and the concept of scope; the notation for many CS algorithms to this day.
• Simula — developed by Ole-Johan Dahl and Kristen Nygaard at the Norwegian Computing Center (1962–67); introduced classes, objects, and inheritance; the first object-oriented programming language; directly influenced Smalltalk, C++, and Java.
• Pascal — designed by Niklaus Wirth (1970); emphasized structured programming and strong typing; widely taught in universities through the 1980s–90s; Apple used a Pascal variant for early Mac development.
• C language — Dennis Ritchie at Bell Labs (~1972); designed to rewrite Unix; portable, systems-level language with low-level access; foundational to C++, Java, Python, and most modern languages in some lineage.
• Basic (BASIC) — Beginners’ All-purpose Symbolic Instruction Code; designed by John Kemeny and Thomas Kurtz at Dartmouth (1964); the most widely used programming language on early home computers (Apple II, Commodore 64, TRS-80).

Third Generation: Integrated Circuits (early 1960s–early 1970s)

• Integrated circuit (IC) — Jack Kilby (Texas Instruments, 1958) and Robert Noyce (Fairchild Semiconductor, 1959) independently developed the IC; multiple transistors on a single chip of semiconductor. Kilby received the Nobel Prize in Physics (2000); Noyce had died in 1990.
• Jack Kilby — Texas Instruments engineer; his first IC (1958) used germanium; also invented the handheld electronic calculator (with TI colleagues, 1967).
• Robert Noyce — co-inventor of the IC using a planar silicon process; co-founded Fairchild Semiconductor (1957) with the Traitorous Eight and later Intel (1968) with Gordon Moore; sometimes called “the Mayor of Silicon Valley.”
• IBM System/360 — landmark mainframe line announced 1964; single compatible architecture across a range of models; established the concept of a software-compatible hardware family.
• DEC PDP series — Digital Equipment Corporation introduced minicomputers (PDP-1, 1960; PDP-8, 1965); far smaller and cheaper than mainframes; widened access to computing in universities and labs. Ken Olsen founded DEC (1957); the VAX superminicomputer (1977) extended the line.
• Time-sharing — CTSS (MIT, 1961) and Multics (Bell Labs/MIT/GE) pioneered allowing multiple users to share a single computer simultaneously.
• Unix — Ken Thompson and Dennis Ritchie at Bell Labs (~1969–70); portable, multi-user operating system; written in C (Ritchie’s language, ~1972); became the foundation for Linux, macOS, BSD, and most server operating systems. The name is a pun on the earlier Multics project.
• Ken Thompson — co-creator of Unix with Ritchie; also designed the B language (precursor to C), the Plan 9 OS, and co-designed the Go programming language at Google; Turing Award 1983 (shared with Ritchie).
• Dennis Ritchie — created the C programming language (~1972) and co-created Unix; Turing Award 1983 (shared with Thompson); often called “dmr”; his death (2011) was widely overshadowed by Steve Jobs’ death the same week.

Fourth Generation: Microprocessors (early 1970s onward)

• Intel 4004 — first single-chip microprocessor marketed commercially (1971); 4-bit, ~2,300 transistors; designed by Federico Faggin, Ted Hoff, and Stanley Mazor for a Japanese calculator company (Busicom). Federico Faggin also designed the Zilog Z80.
• Federico Faggin — Italian-American physicist and engineer; chief designer of the Intel 4004, 8008, and the Zilog Z80; co-founded Zilog (1974).
• Intel 8008 / 8080 — 8-bit successors (1972, 1974); the 8080 was the basis for early personal computers.
• Zilog Z80 — widely used 8-bit microprocessor (1976); powered many home computers including the TRS-80 and early CP/M machines.
• MOS Technology 6502 — 8-bit chip (1975); used in Apple II, Commodore 64, Atari 800, BBC Micro, and the NES; low cost accelerated the home computer market. Chuck Peddle was the primary designer.
• ARM architecture — Acorn RISC Machine; designed at Acorn Computers (UK, 1983–85) by Sophie Wilson and Steve Furber; RISC (Reduced Instruction Set Computer) design emphasizing energy efficiency; now the dominant CPU architecture in smartphones, tablets, and embedded systems worldwide.

The Personal Computer Era

• Altair 8800 — MITS kit computer (January 1975 cover of Popular Electronics); Intel 8080; no keyboard or monitor; programmed by toggle switches; widely regarded as the spark of the personal computer revolution. Ed Roberts of MITS designed the Altair.
• Kenbak-1 — designed by John Blankenbaker (1971); sold via Scientific American; sometimes cited as the first personal computer predating the Altair, though in small quantities.
• Microsoft founding — Bill Gates and Paul Allen wrote a BASIC interpreter for the Altair (1975); incorporated Microsoft 1975. Gates famously dropped out of Harvard to pursue the venture; Allen coined the name “Micro-Soft.”
• Apple I and II — Apple Computer founded by Steve Jobs, Steve Wozniak, and Ronald Wayne (1976); Apple I (1976) designed by Wozniak; Apple II (1977) was the first mass-market home computer with color graphics, widely used in schools. VisiCalc (1979), the first spreadsheet, ran on the Apple II and drove its commercial success.
• Steve Wozniak — designed the Apple I and Apple II almost single-handedly; invented a floppy disk controller using minimal chips; widely regarded as one of the greatest hardware engineers of the PC era.
• CP/M — Control Program for Microcomputers; Gary Kildall’s operating system (1974) dominated 8-bit personal computers; its market position was disrupted when IBM chose DOS instead. Kildall’s company was Digital Research; his failure to seal the IBM deal is one of the great “what-ifs” of computing history.
• VisiCalc — first spreadsheet program; Dan Bricklin and Bob Frankston (1979); ran on Apple II; considered the first “killer app,” driving sales of personal computers to businesses.
• IBM PC — IBM Personal Computer (August 1981); used Intel 8088; IBM chose Microsoft’s MS-DOS (which Microsoft acquired from Tim Paterson as QDOS); open architecture allowed clone makers (Compaq et al.) to create compatible machines, fragmenting control away from IBM. The “IBM compatible” standard became the dominant PC platform.
• MS-DOS — Microsoft Disk Operating System; Microsoft purchased QDOS (“Quick and Dirty OS”) from Tim Paterson of Seattle Computer Products for $50,000 and licensed it to IBM as PC-DOS; the deal made Microsoft’s fortune.
• Lotus 1-2-3 — spreadsheet released 1983; the dominant IBM PC application through the mid-1980s; defeated VisiCalc and drove IBM PC adoption in business.
• Commodore 64 — released 1982; best-selling single personal computer model in history by some estimates; MOS 6510 CPU, 64 KB RAM, SID sound chip.
• Apple Macintosh — introduced January 1984 with a famous Super Bowl ad (“1984,” directed by Ridley Scott); first mass-market computer to popularize the graphical user interface and mouse for general consumers. The ad aired once during Super Bowl XVIII.
• Intel x86 architecture — 16-bit 8086 (1978) → 8088 (IBM PC) → 80286 → 80386 (32-bit, 1985) → Pentium (1993) → Core series; the dominant desktop/laptop CPU architecture through 2026.

Moore’s Law and Semiconductor Industry

• Moore’s Law — Gordon Moore (Intel co-founder) observed in 1965 that the number of transistors on a chip roughly doubled each year; revised to approximately every two years (1975). Used as a planning target by the semiconductor industry for decades.
• Fairchild Semiconductor — key early chip maker; its spinouts (Intel, AMD) formed the nucleus of Silicon Valley.
• Intel — co-founded by Gordon Moore and Robert Noyce (1968); dominated the microprocessor market through the 1990s and 2000s.
• AMD — Advanced Micro Devices (founded 1969); Intel’s primary x86 competitor; introduced 64-bit x86-64 extensions (2003) ahead of Intel.
• TSMC — Taiwan Semiconductor Manufacturing Company (founded by Morris Chang, 1987); pioneered the pure-play foundry model; the world’s largest contract chipmaker as of 2026.
• End of Dennard scaling — ~2006, transistors stopped getting faster as they shrank; industry shifted to multi-core processors.
• Apple Silicon (M-series) — Apple’s ARM-based chips for Mac (M1, 2020); demonstrated performance-per-watt advantages over x86; manufactured by TSMC.

Human-Computer Interaction: GUI and the Mouse

• Doug Engelbart — demonstrated the oN-Line System (NLS) at SRI (1968 “Mother of All Demos”): mouse, hypertext, windows, video conferencing, collaborative real-time editing; most elements in modern computing shown for the first time. Engelbart received the Turing Award in 1997.
• Mouse — Engelbart’s wooden prototype (1964, SRI); co-developed with Bill English; patented 1970; the device was named “mouse” because the cord resembled a tail.
• Xerox PARC — Palo Alto Research Center (founded 1970); developed the Alto (1973), the first computer designed around a GUI; invented Ethernet (Bob Metcalfe, 1973), laser printing, object-oriented programming (Smalltalk, Alan Kay), and WYSIWYG editing. Despite inventing much of modern computing, Xerox failed to commercialize most of it.
• Alan Kay — PARC researcher and visionary; designed Smalltalk and the object-oriented paradigm; proposed the Dynabook concept (a tablet-like portable computer for children) in 1972, decades before the iPad; coined the phrase “the best way to predict the future is to invent it”; Turing Award 2003.
• Xerox Star — first commercial GUI computer (1981); too expensive to succeed commercially but heavily influenced Apple and Microsoft.
• Apple Lisa — first mass-produced personal computer with a GUI (1983); expensive and unsuccessful; succeeded by the Macintosh.
• Windows 1.0 — Microsoft’s first GUI OS (1985); ran on top of MS-DOS; not commercially significant until Windows 3.0 (1990) and Windows 95 (1995, which bundled Internet Explorer).

Operating Systems and Software

• Unix lineage — Unix → BSD (Berkeley, 1977) → SunOS/Solaris; separately, Minix → Linux (Linus Torvalds, 1991, first announced on Usenet); GNU tools + Linux kernel = GNU/Linux.
• Linux kernel — open-source; released under GPLv2; Torvalds famously announced it in August 1991 with “I’m doing a (free) operating system (just a hobby, won’t be big and professional like gnu)”; powers the majority of servers, Android devices, and supercomputers worldwide.
• Linus Torvalds — Finnish-American software engineer; created Linux (1991) and Git (2005); received the Millennium Technology Prize (2012); the Linux kernel codebase is maintained through a distributed open-source model he still oversees.
• GNU Project — Richard Stallman launched the GNU Project at MIT (1983) to create a free Unix-like OS; produced essential tools (gcc, glibc, bash) but lacked a kernel until paired with Linux; GPL (General Public License) written by Stallman (1989) became the most influential open-source license.
• Richard Stallman — founder of the Free Software Foundation (1985) and author of the GPL; introduced the concept of “copyleft”; launched GNU; wrote Emacs and the gcc compiler.
• macOS — Apple acquired NeXT (1997); macOS (originally Mac OS X, 2001) is built on a BSD/Mach Unix foundation.
• Windows NT — Dave Cutler’s architecture (1993); separated from DOS heritage; basis for all modern Windows versions.
• Open-source movement — Richard Stallman launched GNU Project (1983) and wrote the GPL; Eric Raymond’s The Cathedral and the Bazaar (1997) articulated the open-source development model.
• Object-oriented programming — Simula (Ole-Johan Dahl and Kristen Nygaard, 1960s) introduced classes and objects; Smalltalk (Xerox PARC, Alan Kay, 1970s) refined OOP; C++ (Bjarne Stroustrup, 1985) and Java (Sun Microsystems, James Gosling, 1995) brought OOP to mass adoption.
• Java — designed by James Gosling at Sun Microsystems (1995); “write once, run anywhere” via the Java Virtual Machine (JVM); dominant in enterprise and Android app development; originally developed under the name “Oak.”
• Python — designed by Guido van Rossum (1991); emphasizes readability and simplicity; became the dominant language for data science, machine learning, and scripting; van Rossum held the title “Benevolent Dictator For Life” (BDFL) until 2018.
• SQL — Structured Query Language; developed at IBM by Donald Chamberlin and Raymond Boyce (1974), based on Edgar Codd’s relational model (1970); the standard language for relational databases; Oracle, MySQL, PostgreSQL all use SQL dialects.
• Edgar Codd — IBM researcher who proposed the relational model of database management (A Relational Model of Data for Large Shared Data Banks, 1970); Turing Award 1981; the theoretical foundation of all SQL databases.

Networking and the Internet

• ARPANET — U.S. Department of Defense funded network (1969); first packet-switched wide-area network; first message sent October 29, 1969 between UCLA and SRI (the connection crashed after “LO”). Leonard Kleinrock at UCLA supervised the first message; the ARPA director J.C.R. Licklider had earlier envisioned an “Intergalactic Computer Network” (1963).
• Packet switching — independently developed by Paul Baran (RAND) and Donald Davies (NPL UK) in the 1960s; data split into packets routed independently, more robust than circuit switching.
• TCP/IP — Transmission Control Protocol / Internet Protocol; designed by Vint Cerf and Bob Kahn (1974 paper “A Protocol for Packet Network Intercommunication”); adopted as ARPANET standard 1983; the foundational protocol suite of the internet. Cerf is often called “the Father of the Internet”; both received the Presidential Medal of Freedom (2005).
• DNS — Domain Name System; Paul Mockapetris (1983); translates human-readable domain names to IP addresses.
• World Wide Web — Tim Berners-Lee at CERN (proposal 1989 titled “Information Management: A Proposal,” first site online 1991); HTTP protocol, HTML markup, URLs; distinct from the internet (the physical network). Berners-Lee’s original proposal was noted by his supervisor Mike Sendall as “Vague but exciting.” Berners-Lee received the Turing Award (2016).
• NCSA Mosaic — first graphical web browser (Marc Andreessen and Eric Bina, NCSA, 1993); made the web accessible to non-technical users; led directly to Netscape Navigator.
• Tim Berners-Lee — British computer scientist; invented the World Wide Web at CERN; chose not to patent HTTP or HTML, making the web openly available; founded the W3C (1994) to develop web standards; knighted (2004).
• Netscape / browser wars — Netscape Navigator (1994) dominated early web browsing; Microsoft bundled Internet Explorer with Windows 95/98 and won the “first browser war”; antitrust suit followed. Netscape’s IPO (August 1995) is often marked as the symbolic start of the dot-com era. Marc Andreessen later co-founded the VC firm Andreessen Horowitz (a16z).
• JavaScript — designed by Brendan Eich at Netscape in 10 days (1995); originally called Mocha, then LiveScript; became the universal language of the web browser; Node.js (2009) extended it to server-side use.
• Google — Larry Page and Sergey Brin, Stanford PhD project (PageRank algorithm, ~1996); incorporated 1998; PageRank ranked pages by inbound links weighted by the linker’s own rank.
• Wi-Fi (802.11) — IEEE standard ratified 1997 (802.11); Wi-Fi Alliance formed 1999; made wireless home and office networking ubiquitous.

The Dot-Com Era and Web 2.0

• Dot-com bubble — explosive growth of internet companies 1995–2000; NASDAQ peaked March 2000 at ~5,048; collapse wiped out ~$5 trillion in market value by 2002.
• Amazon — Jeff Bezos, 1994 (online bookstore); grew into cloud computing (AWS, 2006) and e-commerce platform.
• eBay — Pierre Omidyar, 1995; pioneered consumer-to-consumer online auction and marketplace.
• Web 2.0 — term popularized ~2004 (Tim O’Reilly); characterized by user-generated content, social networking, Ajax-driven interfaces; contrasted with static “Web 1.0” sites.
• Wikipedia — launched January 2001 (Jimmy Wales and Larry Sanger); free, collaboratively edited encyclopedia; one of the most visited websites.
• Social media — Friendster (2002), MySpace (2003), Facebook (Mark Zuckerberg, launched 2004 at Harvard); Twitter (Jack Dorsey, 2006); YouTube (2005, acquired by Google 2006); LinkedIn (Reid Hoffman, 2003).

Mobile and Smartphones

• GSM / cellular — first-generation analog cellular (1G) in 1980s; GSM digital standard (2G) deployed 1991; SMS text messaging became ubiquitous; 3G data (~2001) enabled mobile internet; 4G LTE (~2009) enabled streaming.
• Palm Pilot — Jeff Hawkins, 1996; highly successful PDA (personal digital assistant) before smartphones; introduced Graffiti handwriting recognition.
• BlackBerry — Research In Motion (RIM); dominant smartphone in enterprise ~2003–2010; physical QWERTY keyboard; pioneered mobile email push.
• iPhone — Steve Jobs announced January 9, 2007; combined phone, widescreen iPod, and internet communicator; capacitive multi-touch screen; no physical keyboard; App Store launched 2008; transformed the mobile industry.
• Android — Google acquired Android Inc. (2005); open-source Linux-based OS; first Android phone: HTC Dream / T-Mobile G1 (2008); became the dominant mobile OS by market share.
• App Store / Google Play — curated software distribution; App Store launched July 2008; created multibillion-dollar developer ecosystems.
• 5G — fifth-generation cellular, deployed commercially ~2019 onward; sub-6 GHz and millimeter-wave bands; multi-gigabit peak speeds; key for IoT and low-latency applications.

Cloud Computing and Big Data

• AWS (Amazon Web Services) — launched 2006; S3 object storage and EC2 compute instances; pioneered Infrastructure-as-a-Service (IaaS); established the public cloud model.
• Cloud providers — Amazon AWS, Microsoft Azure (2010), Google Cloud Platform (2011); together dominate the global cloud market.
• Virtualization — VMware (founded 1998) commercialized x86 virtualization; fundamental to cloud computing and data center efficiency.
• Hadoop — open-source framework for distributed storage and processing of big data (MapReduce model); inspired by Google’s GFS and MapReduce papers (2003–04); donated to Apache by Yahoo (~2006).
• SaaS — Software-as-a-Service; Salesforce (Marc Benioff, 1999) pioneered enterprise SaaS (CRM); model now dominant for business software.

AI, Machine Learning, and Recent Milestones

• Dartmouth Conference — summer 1956 at Dartmouth College; John McCarthy coined the term “artificial intelligence”; participants included Marvin Minsky, Claude Shannon, Herbert Simon, and Allen Newell; formally launched AI as a field.
• John McCarthy — coined “artificial intelligence” (1956); designed LISP (1958); invented time-sharing; proposed the concept of utility computing; Turing Award 1971.
• Marvin Minsky — co-founder of the MIT AI Lab; wrote Perceptrons (1969, with Papert); proposed the “Society of Mind” theory; Turing Award 1969; influential in both symbolic AI and early neural network critique.
• Perceptron — Frank Rosenblatt (1958); early neural network model; Minsky and Papert’s Perceptrons (1969) critique contributed to an “AI winter.”
• Expert systems / AI winters — rule-based expert systems (1970s–80s) followed by reduced funding when promises were not met (“AI winters” ~1974–80, ~1987–93).
• Backpropagation — algorithm for training multi-layer neural networks; popularized by Rumelhart, Hinton, and Williams (1986); foundational to deep learning.
• Deep learning breakthrough — AlexNet (Krizhevsky, Sutskever, Hinton, 2012) won ImageNet Large Scale Visual Recognition Challenge with a top-5 error rate of 15.3%, far below the next competitor; reignited the field.
• ImageNet — large-scale visual database created by Fei-Fei Li (Stanford) starting 2006; the annual ImageNet competition (ILSVRC, 2010–2017) became the benchmark driving the deep learning revolution.
• GPU computing — NVIDIA CUDA (2007) enabled GPUs to be used for general-purpose parallel computing; essential for training deep neural networks.
• Transformer architecture — “Attention Is All You Need” (Vaswani et al., Google, 2017); attention-based architecture that replaced RNNs for sequence modeling; basis for all modern large language models.
• GPT series — OpenAI’s Generative Pre-trained Transformers; GPT-3 (2020, 175B parameters) demonstrated few-shot learning; ChatGPT (launched November 2022) reached 100 million users in ~2 months.
• AlphaGo / AlphaFold — DeepMind’s AlphaGo defeated world Go champion Lee Sedol 4-1 (2016); earlier AlphaGo defeated Fan Hui (2015). AlphaFold2 (2020) predicted protein structures at near-experimental accuracy, winning the CASP14 competition decisively; considered a landmark for biology.
• Deep Blue — IBM chess computer that defeated world champion Garry Kasparov in a six-game match (May 1997); first computer to beat a reigning world chess champion in match play; Kasparov had won their first match in 1996.
• Large language models (2023–2026) — GPT-4, Claude, Gemini, Llama, Mistral; rapidly deployed in products; multimodal models handle text, images, and audio; context windows expanded to millions of tokens.

Key Figures Summary

Person	Contribution
Charles Babbage	Difference Engine; Analytical Engine concept
Ada Lovelace	First algorithm; visionary notes on Analytical Engine
George Boole	Boolean algebra
Herman Hollerith	Punched-card tabulation; founded company that became IBM
Alan Turing	Turing machine; computability theory; Bombe at Bletchley
Claude Shannon	Information theory; linking Boolean algebra to circuits
John von Neumann	Stored-program architecture
Grace Hopper	COBOL; first compiler (A-0, 1952); popularized “debugging”
Jack Kilby / Robert Noyce	Integrated circuit (independently, 1958–59)
Doug Engelbart	Mouse; GUI; hypertext (1968 demo)
Gordon Moore	Moore’s Law; Intel co-founder
Dennis Ritchie	C language; Unix (with Ken Thompson)
Bill Gates / Paul Allen	Microsoft; MS-DOS; Windows
Steve Jobs / Steve Wozniak	Apple; Macintosh; iPhone
Tim Berners-Lee	World Wide Web; HTTP; HTML
Linus Torvalds	Linux kernel
Larry Page / Sergey Brin	Google; PageRank
Geoffrey Hinton	Deep learning; backpropagation; neural networks