The ALGOL 68 Programming Language

Published on 02 May 2020 (Updated: 11 May 2022)

The ALGOL 68 Programming Language

Welcome to the Algol68 page! Here, you'll find a description of the language as well as a list of sample programs in that language.


ALGOL 68, also known as Algorithmic Language 68, is a successor to the ALGOL 60 language. As the name suggests, ALGOL 68 first appeared in 1968 as an imperative programming language.

That said, ALGOL 68 has a much wider scope than ALGOL 60. For instance, ALGOL 68 includes user-declared types, expression-based syntax, concurrency, and even slicing.

Of course, I think the most interesting language feature is the overwhelming list of reserved words which includes 60 different symbols. Most of these symbols I couldn't even guess their purpose. For example, what do you think esac does? How about ouse? James Jones offers a great explanation:

Oh about some of these keywords... Algol 68 has a convention of ending constructs with the reverse of the keyword that begins them. So if statements end with fi, the loop body that starts with do ends with od, and case is ended with esac.

In general though, I find that most of the symbols are pretty typical. Many of which provide either control flow or iteration. Meanwhile, others provide typing. So, overall the language seems pretty tame. Feel free to check out the Wikipedia page for the full syntax and features list.