99 Bottles of Beer on the Wall - Algol 68 version.
A history of ALGOL 68 - at ACM Digital Library. Abstract article from the second ACM SIGPLAN conference on History of programming languages (1993). Full text for ACM members only.
A Practical Guide to Algol 68 - Book by Frank G. Pagan at Amazon.
A Shorter History of Algol 68 - A short text of the language's history.
Algol 68 - List of 3 extant implementations with descriptions and some sample programs.
Algol 68 - 25 Years in the USSR - Interesting history of Algol 68 in the USSR and the Leningrad compiler.
Algol 68 home page - There are EMX and Linux ports of A68ToC, the MC Revised ALGOL 68 Test Set an early version of the OCCL compiler and other Algol 68 related items.
Algol 68 Revised Report - in TeX, Postscript or Acrobat pdf.
ALGOL 68 slideshow - A short overview of the main features of Algol 68.
Algol 68 to C - Portable translator to allow compiling Algol 68 code, and some example Algol 68 programs in the same directory.
An Introduction To Algol 68 - The second ACM SIGPLAN conference on History of programming languages.
An Optimized translation process and its application to ALGOL 68 - Book at Amazon.
Charles Lindsey's Home Page - Algol 68S compilers for Sun3, Sun Sparc, Atari ST and Acorn Archimedes.
ELLA - Contains the source for an Algol 68 to C translator.
Home Page of W. B. Kloke - Contains an ongoing project to create a machine readable Algol 68 Revised Report and numerous Algol 68 related links.
IFIP Technical Committee 2 - The group that developed the Algol language.
László Csirmaz - There is an Algol 68 interpreter for PCs here.
Marc's programming projects - An (unfinished) project to write an Algol 68 compiler (source code provided in CWEBx).
Marcel van der Veer - There is an implementation of Algol 68 called Algol68G for PowerPCs (e.g Macs) here.
OCCL Home Page - Commercial Algol 68 compilers for OS/2, Linux PCs, Windows'95 and Windows/NT, SUNOS 4.1.3 and Inmos Transputer family.
PL Language Info: Algol 68 - Brief table of traits.
Revised report on the algorithmic language ALGOL 68 - Book at Amazon.
Services - LANIT-TERCOM have experience in Algol 68 and produce an Algol 68 compiler for MS-DOS
Software Engineering with Algol 68 - Sian Leitch's site with Debian port of Ctrans with extensive preludes and Web68