Rather than "tracing its roots to it", I'd say "has some roots in it". Algol per se hardly made a ripple in the US market, partly due to politics and habit, but also because it didn't espouse separate compilation. However, as asserted above, it had a profound impact on language designers and counts many languages as descendants. To bring the subject back to Unix, C followed Fortran's modularity and Algol's block structure. (But it reached back across the definitive Algol 60 to pick up the "for" statement from Algol 58.) Like PL/I, it also borrowed the indispensable notion of structs from business languages (Flowmatic, Comtran, Cobol). It adopted pointers from Lisp, as polished by BCPL (pointer arithmetic) and PL/I (the -> operator). For better or worse, it went its own way by omitting multidimensional arrays. So C has many roots. It just isn't fashionable in computer-language circles to highlight Cobol in your family tree. Doug