I attempted the last Advent of Code in Algol 68 using a68g. I didn't quite finish it, but I think this is probably one of the larger repositories of Algol 68 source code out there :D
The idea of using Algol 68 was also quite popular in the Soviet academic circles (loosely tied with the military-industrial complex) throughout the 1970-80s. Right before this interest had expired Algol 68 was seen as a direct competitor to Ada. (After that C became all the rage.)
In the context of writing a language mode for an editor, they don't share anything significant.
The revised report says the following:
"Algol 68 has not been designed as an expansion of Algol 60 but rather as a completely new language based on new insight into the essential, fundamental concepts of computing and a new description technique."
Perhaps related: I understood that the Liverpudlian Fortran 90 compiler done by NA Software was based on an Algol 68 compiler (I don't know which one). I thought that was odd at the time, but it probably wasn't, and presumably shows the direct relevance to more recent language evolutions.
Algol is so interesting that the vast majority of developers are absolutely repelled from languages that don't resemble it. Algol is ultimately why javascript looks like it looks rather than looking like other languages that it's more like, or why Erlang terrified people but Elixir soothes people.
There is quite a difference between Algol 60 (what I suppose you're refering to) and Algol 68. Most of todays languages are inspired by Algol 60 and Simula 67, including C, C++, Pascal, Java, Python and others. Records and unions were first proposed by Hoare in 1965 (Algol Bulletin 21) and adopted by Wirth for his Algol successor proposal which eventually led to Pascal; it was also adopted in Simula 67 by Dahl and Nyguard who extended the concept to what we today know as object-oriented programming. Algol 68 instead is based on the proposal by Wijngaarden which followed a different philosophy than Pascal or Simula.
