Free (released under the GNU General Public License) disk defragment and optimize utility for Windows 2000/2003/XP/Vista/X64. Completely automatic and very easy to use, fast, low overhead, with two optimization strategies, and can handle floppies and USB disks/sticks. Included are a Windows version, a commandline version (for scheduling by the task scheduler or for use from administrator scripts), a screensaver version, a DLL library (for use from programming languages), and versions for Windows X64.
一个免费的基于GNU General Public License的Windows磁盘整理和优化软件，支持Windows 2000/2003/XP/Vista/X64。全自动并非常易于实用，并支持USB磁盘和存储卡的整理，它利用微软的标准磁盘整理API制作，整理磁盘彻底，对NTFS的兼容性好并且不损害数据。
Download : JkDefrag 3.14 | 64-Bit
HomePage: http://www.kessels.com/JkDefrag/
JGDefragGUI, This program is a GUI for the Opensource Defrag program jkdefrag.
Download: http://www.paehl.com/open_source/?JGDefragGUI