Hello,
Well,
O&O Defrag 2000 is freeware, but it's an very old version (and no more supported) - the latest I found was 3.5.
The newest version of O&O Defrag (8.6) you can get for a price of 49.95 USD.
Concerning JKDefrag it should be mentioned, that you have to download JKDefragGUI, otherwise you do have a Command-line utility without graphical interface to configure it.
Jean-Paul