First presented as a keynote address in 1973 and later widely reprinted, this essay by Tony Hoare offers practical guidance on how programming languages should be designed. It draws on his experience of both using and implementing them.

Hoare argues that a language should serve the programmer, above all by being simple, so that its rules can be understood in full. He stresses qualities such as security, so that errors are detected rather than concealed; readability; and fast, efficient translation. He is sceptical of languages that accumulate features at the cost of clarity.

Throughout, he treats simplicity not as a limitation but as a discipline that makes programs easier to write correctly and to reason about. The essay became a much-cited statement of design principles, reflecting Hoare’s wider concern with reliability and elegance in computing.