Kathleen Booth née Britten (1922 –) is credited with writing the first assembly language and the design of the assembler and autocode (ARC and APE(X)C) for the first computer systems at Birkbeck College, University of London.
Kathleen Booth worked at Birkbeck College, 1946–62. She traveled to the United States as Andrew Booth's research assistant in 1947, visiting with John von Neumann at Princeton. Upon returning to the UK, she co-authored "General Considerations in the Design of an All Purpose Electronic Digital Computer," describing modifications to the original ARC redesign to the ARC2 using a von Neumann architecture. Part of her contribution was the ARC assembly language. She also built and maintained ARC components.
Kathleen and Andrew Booth's team at Birkbeck were considered the smallest of the early British computer groups. From 1947 to 1953, they produced three machines: ARC (Automatic Relay Computer), SEC (Simple Electronic Computer), and APE(X)C (All-purpose Electronic (Rayon) Computer). She and Mr. Booth worked on the same team. He built the computers and she programmed them.  This was considered a remarkable achievement due the size of the group and the limited funds at its disposal. Although APE(X)C eventually led to the HEC series manufactured by the British Tabulating Machine Company, the small scale of the Birkbeck group did not place it in the front rank of British computer activity.
Booth regularly published papers concerning her work on the ARC and APE(X)C systems and co-wrote "Automatic Digital Computers" (1953) which illustrated the 'Planning and Coding' programming style. She co-founded the School of Computer Science and Information Systems in 1957 at Birkbeck College along with Andrew Booth and J.C. Jennings. In 1958, she taught a Programming course.
In 1958, Booth wrote a book describing how to program APE(X)C computers, .
Booth's research on neural networks led to successful programs simulating ways in which animals recognize patterns and recognize character. She and her husband resigned suddenly from Birkbeck College in 1961 after a chair was not conferred on her husband despite his massive contributions and an I.C.T. Type 1400 Computer was donated to the Department of Numerical Automation but was in fact installed in the London School of Hygiene and Tropical Medicine.
- Johnson, Roger. "50 Years of Computing at Birkbeck". Birkbeck College, University of London. April 2008. http://www.dcs.bbk.ac.uk/50years/50yearsofcomputing.pdf
- Dyson, George (2012). Turing's Cathedral: The Origins of the Digital Universe. Pantheon Books. p. xvii. ISBN 978-0375422775.
- Booth, Kathleen HV, "Machine language for Automatic Relay Computer", Birkbeck College Computation Laboratory (University of London)
- IT Honor Roll
- School of computer science and information systems: A short history (PDF), 50 years of Computing, UK: Birkbeck School of Computing, 2008.
- Alan Turing and His Contemporaries: Building the World's First Computers, ISBN 978-1-78017-105-0
- "History", About, UK: Birkbeck School of Computing.
- Kathleen Booth (nee Britten) at the ARC relay, parallel, A.U. which she constructed, UK: Birkbeck school of Comptuing, 1948.
- Lavington, Simon (1980). Early British computers: the story of vintage computers and the people who built them. Manchester: Manchester University Press. p. 62. ISBN 0719008034.
- Campbell-Kelly, Martin (April 1982), "The Birkbeck College Machines", Annals of the History of Computing (IEEE) 4 (2)
- Cliff B Jones, John L Lloyd, ed. (1998). Dependable and historic computing. Berlin: Springer-Verlag. p. 27. ISBN 978-3-642-24540-4.
- Booth, Kathleen HV (1958), Programming for an Automatic Digital Calculator, London: Butterworths.
- Booth, Andrew D; Britten, Kathleen HV (Sep 1947), "Principles and Progress in the Construction of High-Speed Digital Computers", Quart. Journ. Mech. and Applied Math..
- Coding system for the APE(X)C, AU: Murdoch.
- Booth A.D. and Britten K.H.V. (1947) Coding for A.R.C., Institute for Advanced Study, Princeton
- Booth A.D. and Britten K.H.V. (1947) General considerations in the design of an all-purpose electronic digital computer, Institute for Advance Study, Princeton
- Booth A.D. and Britten K.H.V. (1948) "The accuracy of atomic co-ordinates derived from Fourier series in X-ray crystallography Part V", Proc. Roy. Soc. Vol A 193 pp305–310
- Booth A.D. and Booth K.H.V. (1953) Automatic Digital Calculators, Butterworth-Heinmann (Academic Press) London