March 2014 update

Task/Sierpinski-triangle/PARI-GP/sierpinski-triangle.pari

@@ -0,0 +1,11 @@
+Sierpinski(n)={
+  my(s=2^n-1);
+  forstep(y=s,0,-1,
+    for(i=1,y,print1(" "));
+    for(x=0,s-y,
+      print1(if(bitand(x,y)," ","*"))
+    );
+    print()
+  )
+};
+Sierpinski(4)

Task/Sierpinski-triangle/Perl-6/sierpinski-triangle.pl6

@@ -3,7 +3,7 @@ sub sierpinski ($n) {
     my $space = ' ';
     for ^$n {
         @down = @down.map({"$space$_$space"}), @down.map({"$_ $_"});
-        $space ~= $space;
+        $space x= 2;
     }
     return @down;
 }

Task/Sierpinski-triangle/REXX/sierpinski-triangle.rexx

@@ -5,13 +5,13 @@ if mk==''         then mk='*'          /*use the default of an asterisk.*/
 if length(mk)==2  then mk=x2c(mk)      /*MK was specified in hexadecimal*/
 if length(mk)==3  then mk=d2c(mk)      /*MK was specified in decimal.   */
 numeric digits 12000                   /*this otta handle the die-hards.*/
-
+                                       /* [↓]  the blood-'n-guts of pgm.*/
    do j=0  for n*4;  !=1;  z=left('',n*4-1-j)        /*indent the line. */
-             do k=0  to j              /*build the line with  J+1  parts*/
-             if !//2==0  then z=z'  '  /*it's either a blank,  or  ...  */
+             do k=0  for j+1           /*build the line with  J+1  parts*/
+             if !//2==0  then z=z'  '  /*it's either a blank,  or  ···  */
                          else z=z mk   /*it's one of them thar character*/
              !=!*(j-k)%(k+1)           /*calculate a handy-dandy thingy.*/
-             end   /*k*/
+             end   /*k*/               /* [↑]  finished building a line.*/
    say z                               /*display a line of the triangle.*/
-   end             /*j*/
+   end             /*j*/               /* [↑]  finished displaying tri. */
                                        /*stick a fork in it, we're done.*/