Source code in the setl programming language

h := open('unixdict.txt', "r");
anagrams := {};
while not eof(h) loop
  geta(h, word);
  if word = om or word = "" then
    continue;
  end if;
  sorted := insertion_sort(word);
  anagrams{sorted} with:= word;
end loop;

max_size := 0;
max_words := {};
for words = anagrams{sorted} loop
  size := #words;
  if size > max_size then
    max_size := size;
    max_words := {words};
  elseif size = max_size then
    max_words with:= words;
  end if;
end loop;

for w in max_words loop
  print(w);
end loop;

-- GNU SETL has no built-in sort()
procedure insertion_sort(A);
  for i in [2..#A] loop
    v := A(i);
    j := i-1;
    while j >= 1 and A(j) > v loop
      A(j+1) := A(j);
      j := j - 1;
    end loop;
    A(j+1) := v; 
 end loop;
 return A;
end procedure;