I'm sorry Lonkero, but I think you missed it.
I backed out your changes to the central loop as it was the same
length as mine, but used ('$a ') which I don't think is allowed.
You reduced the Sort UDF by 3 but missed your own trick,
namely setting the loop var to zero on a swap,
allowing me to remove the outer loop.
Golf score = 472
code:
FUNCTION anagram($J)
DIM $u, $,$a,$b,$c, $I,$O
$u = UBound($J)
$I = S($J)

FOR $ = 0 TO $u
  DIM $t[20]
  FOR $a = 1 TO Len($I[$])
    $t[$a] = Substr($I[$],$a,1)
  NEXT
  $J[$] = Join(S($t),'')
NEXT

FOR EACH $a IN $J
  DIM $,$d
  FOR $c = 0 TO $u
    IF $a = $J[$c]  AND $a
      $ = $ + ' ' + $I[$c]
      $d = 1 + $d
      $J[$c] = 0
    ENDIF
  NEXT
  IF $d > 1
    $O = $O +$b+ Chr($d)+$
    $b = #
  ENDIF
NEXT

$ = ''
IF $O
  $ = S(Split($O,#))
  FOR $a = 0 TO Ubound($)
    $[$a] = Substr($[$a],3)
  NEXT
ENDIF
$anagram = $
ENDFUNCTION
;
FUNCTION S($)
DIM $t
FOR $S = 1 TO UBound($)
  $t = $[$S-1]
  IF $[$S] < $t
    $[$S-1] =$[$S]  $[$S] =$t
    $S = 0
  ENDIF
NEXT
$S = $
ENDFUNCTION