TUFS is Tuxera’s customized fork of MacFUSE, used in Tuxera NTFS for Mac.
Like its parent project, MacFUSE, it is published as open source for reference. It is however customized to work seamlessly together with the driver component in Tuxera NTFS for Mac and not a general-purpose solution. For a general-purpose MacFUSE-derivate based on Tuxera’s MacFUSE modifications, see:
TUFS is released under the same license as MacFUSE (mostly BSD with certain components under LGPL and APSL). See COPYING.txt for the whole license text.