You can grab the source for free from Tuxera for free, however.
As of OS X 10.6 you can natively enable NTFS support, though your mileage may vary.
The version is free of charge for all previously registered users.
As it is usual in many Linux-related configurations and tweaks, the process was full of unsupported and experimental installations, system errors, and hours of forum reading activities. If you’ve had the need of dealing with NTFS partitions on your Mac before, I can assume it is highly possible you already know fit is not easy, it is not standard, and it is not remotely enjoyable to work (and with work I mean R/W) with NTFS disks at all on a the Apple operative system today.
Probably, as a Mac user and, knowing that Windows is the main force behind the operative system’s universe, you would think that accomplishing the task of working with NTFS volumes on the Mac OS X would be easy. If you don’t know the right tool, the experience could be as frustrating as it is on any other system besides Windows, even in those we like to see as inferior systems.
The main purpose behind this article is to share with you a bit of my experience trying to find that proper application and hopefully save you from making the same mistakes.
As with 99% of the times I need to find a way to solve something, I started at Google when I noticed I could not use my NTFS disk on the Mac.
Tuxera NTFS can be used as a full-featured evaluation version for 15 days, after which the user can unlock the software with an official license key to retain full product functionality.
Free solutions FUSE for OS X - Successor to Mac FUSE NTFS-3G Last updated 2010, pretty much abandoned in favour of the Paid version, Tuxera, unless you want to build from source.It also offers some additional features to its open source counterpart, NTFS-3G, along with commercial support.Tuxera NTFS can be used as a full-featured evaluation version More...Follow this writeup by Mac OS X Hints if you're interested but I'd use the Mac FUSE method over this one.Keep in mind that neither of these methods are fully supported.Tuxera NTFS is a commercial NTFS driver developed from the popular open-source NTFS-3G driver, which is a natural part of all major Linux distributions, and also has lots of users on Mac OS X, Free BSD, Solaris, and Net BSD.