NTFS

The NT File System, introduced with Windows and later modified in Windows 2000 to support compression. It was further enhanced in XP, 7, etc., but not that much - most of the new features (like encryption) have caused more trouble than they’re worth.

There are several kinds of support on Mac:

1. The base OS supports read-only access to NTFS volumes
2. There has long been an open-source effort spanning a number of operating systems that has recently gone commercial and seems to have reached some sort of understanding with Microsoft regarding the IPR involved.
3. Paragon has long had a commercial driver that integrates (very) smoothly¹ with the OS, including adding the appropriate options to Disk Utility for formatting disks and partitions.