Algol 68 version.

Algol 68S compilers for Sun3, Sun Sparc, Atari ST and Acorn Archimedes.

Contains the source for an Algol 68 to C translator (but site now seems dead).

Ongoing project to create machine readable Algol 68 Revised Report (this version in HTML).

By C.H. Lindsey; ACM Digital Library, 1993, ISSN 0362-1340. Abstract of article from the Second ACM SIGPLAN Conference on History of Programming Languages, 1993. Full text for ACM members only.

Springer-Verlag, ISBN 0387075925. [Amazon.com]

A fairly fully featured Algol 68 implementation (interpreter) for Linux, BSD and MacOS. Author of Algol68G is Marcel van der Veer. [Open source, GPL]

The second ACM SIGPLAN conference on History of programming languages.

Portable translator to allow compiling Algol 68 code, and some example Algol 68 programs in the same directory.

A brief description of ALGOL 68 System implemented on Cm*.