http://www.ntfs-3g.org/ The NTFS-3G driver is an open source, freely available read/write NTFS driver for Linux and other operating systems. It provides safe and fast handling of the Windows XP, Windows Server 2003, Windows 2000 and Windows Vista file systems. Most POSIX file system operations are supported, with the exception of full file ownership and access right support.
http://fuse.sourceforge.net/ - Implement userspace driver - With FUSE it is possible to implement a fully functional filesystem in a userspace program.
http://www.linux-ntfs.org/ - The goals of the Linux-NTFS project are to develop reliable and full feature access to NTFS by the Linux kernel driver, and by a user space filesystem (ntfsmount), and to provide a wide collection of NTFS utilities (ntfsprogs) and a developer's library (libntfs) for other GPLed programs. We have achieved already a lot, with high quality results.
Information in this area is meant for use by CSCF staff and is not official documentation, but anybody who is interested is welcome to use it if they find it useful.