Algol 60 was considered, by Tony Hoare, to be " a language so far ahead of its time that it was not only an improvement on its predecessors but also on nearly all its successors. "
Most languages designed since Algol have been fairly strongly based on its design, notably including:
Block structured statements
Variable scoping based on block structure
Structured control statements - If/then/else
Oxford and Cambridge Compilers Ltd offer Algol68 for OS/2, Win32, Solaris, and Linux.
CTrans - a portable implementation of the high-level language Algol 68 with a translator producing C source code.
Algol-like language that translates into Common Lisp