C langauge question

int
add(a, b)
  int a;
  int b;
{
}

Rookie question. What's the benefits of this type of declaration? Also, are there any books that teach this indent style? The GNU C Library seems to make use of it. And so does Julian Assange:
http://ftp.cerias.purdue.edu/pub/tools/unix/scanners/strobe/strobe/strobe.c

Anyway, normal people, like me, use Lisp-style

int
main (int argc
     ,char **argv
     ,void *envp)
     {printf("Hello, World!");
      return 0;}

but really hardcore hackers never use C/C++ at all, they do everything in Lisp.