Source files for both the core linuxcnc & libmnl are forked and munged from a NIST project known as the Enhanced Machine Control (EMC).
The source code for this is public domain. One can NOT take PD code, claim copyright, and then slap an arbitrary license on it.
I don't believe this is a correct statement. Whilst the origins of
LinuxCNC are in the EMC project, it is actually based on EMC2. The
EMC2 copyright statement states:
"Notice: Most of EMC2 is covered by the GNU General Public
License. Some portions are covered by the GNU Lesser
General Public License (mostly interface definitions).
Both licenses are included in their entirety below.
Much of EMC2 is derived from EMC1, a work of Fred Proctor, Tom
Kramer, Will Shackleford, and others. That work was originally
released into the public domain. It was used as the basis of
EMC2, but received extensive modifications. EMC2 is NOT public
domain. Anyone wishing to use the public domain code in a way
that is not compatible with the (L)GPL must locate the original
EMC1 code - they may NOT use EMC2."
Reviewing source files for libnml they state:
License: GPL Version 2
We should be very careful arbitrating over decades old code as the
original context can easily be lost.
Rod Webster
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