Maurice Wilkes in the context of Stored-program computer

In computing, assembly language (alternatively assembler language or symbolic machine code), often referred to simply as assembly and commonly abbreviated as ASM or asm, is any low-level programming language with a very strong correspondence between the instructions in the language and the architecture's machine code instructions. Assembly language usually has one statement per machine code instruction (1:1), but constants, comments, assembler directives, symbolic labels of, e.g., memory locations, registers, and macros are generally also supported.

The first assembly code in which a language is used to represent machine code instructions is found in Kathleen and Andrew Donald Booth's 1947 work, Coding for A.R.C.. Assembly code is converted into executable machine code by a utility program referred to as an assembler. The term "assembler" is generally attributed to Wilkes, Wheeler and Gill in their 1951 book The Preparation of Programs for an Electronic Digital Computer, who, however, used the term to mean "a program that assembles another program consisting of several sections into a single program". The conversion process is referred to as assembly, as in assembling the source code. The computational step when an assembler is processing a program is called assembly time.

Stanley Gill (26 March 1926 – 5 April 1975) was a British computer scientist credited, along with Maurice Wilkes and David Wheeler, with the invention of the first computer subroutine.

The Preparation of Programs for an Electronic Digital Computer (sometimes called WWG, after its authors' initials) was the first book on computer programming. Published in 1951, it was written by Maurice Wilkes, David Wheeler, and Stanley Gill of Cambridge University. The book was based on the authors' experiences constructing and using EDSAC, one of the first practical computers in the world.