libraw1394 is the only supported interface to the kernel side raw1394 of
the Linux IEEE-1394 subsystem, which provides direct access to the connected
1394 buses to user space. Through libraw1394/raw1394, applications can
directly send to and receive from other nodes without requiring a kernel driver
for the protocol in question.

The reason for making a library the interface to the kernel is to avoid
a program dependency on the kernel version, which would hinder development and
optimization of raw1394. If development changed the protocol and made it
incompatible with previous versions only the libraw1394 has to be upgraded to
match the kernel version (instead of all applications).