PHP 4.06 with Freetype 2 and GD 2 does not anti-alias.
In the documentation it says that anti-aliasing can only be disabled by using a negative color (-$black). On my system PHP does not anti-alias; no matter if I am using positiv or negative values.
That's the code:

        $im = ImageCreateFromJpeg ("$motiv");
        $white = imagecolorclosest ($im, 255, 255, 255);
        $black = imagecolorclosest ($im, 0, 0, 0);
               ...

        $data = imagettftext($im, $karten_fontsize, 0, 
          $newx, $xstart, $black, $karten_font, $mytext[$o]);

It works but it just doesn't anti-alias.

     Hans