- Influenced C's type system. I'm just going to quote Dennis Ritchie on this: "The scheme of type composition adopted by C owes considerable debt to Algol 68, although it did not, perhaps, emerge in a form that Algol's adherents would approve of. The central notion I captured from Algol was a type structure based on atomic types (including structures), composed into arrays, pointers (references), and functions (procedures). Algol 68's concept of unions and casts also had an influence that appeared later."
- Influenced bash's syntax (fi, esac)
- I'm not sure if this counts as an influence or not, but objections to Algol 68's design lead Niklaus Wirth to revive his earlier proposal for a new version of Algol, called Algol W, and ultimately evolve it into Pascal.