Unfortunately, the 4.0 release of the software has been renamed MyDefrag, and it has been released under a closed-source, non-Free license.
The newest release, MyDefrag, has built-in scripting capabilities and claims to have improved the speed and memory usage of JkDefrag, while still relying on the underlying API of the built-in Windows drive defragmenter.
The name change is summarized on the JkDefrag page, reading:
It is no longer the "JK" (Jeroen Kessels) defragger, but "my" (your) defragger!
How can a closed-source piece of shareware ever be "my" software? Software written and released under a Free Software license, like JkDefrag was, is truly "my software" because users have access and rights over the code in that software.
Shareware has no such promises as are given under the GPL or other Free Software licenses; in fact the license for this software now reads that "J.C. Kessels or another party may require the user to ... pay service charges related to providing MyDefrag to the user". Meaning, where once JkDefrag was Free software (in both senses of the term), now MyDefrag may end up costing you money if the company decides to charge, perhaps even retroactively. Not for the license mind you, but for just Providing the software to you.
The last release of JkDefrag is still available, along with the GPL source code. Although I cannot code, it would be great if this project were kept alive to help MSWindows machines survive. Not that their demise would be a bad thing, and in fact something that security professionals and FLOSS supporters everywhere would relish.
