Seriously, mac programs are more often than not .sit files. Then you have .img and .dmg files. And sometimes .bin and .hqx and of course the .zip file (just to confuse us mac users). Here we go, sit are stuffit files. img and dmg open with disk copy or cd burning software like toast,(dmg are os10, img are classic and os9 or lower). bin and hqx open with suffit also. And the .zip mostly for windows unless they say mac don't bother. They open with stuffit also. As for the other part of the question, document files? Like .doc files or are you trying to download something like mp3's and they so up on your computer as generic document files. And include the os you use if you can. It all helps...