License issues

[Philip N Daly <pnd@noao.edu>]

Victor,

At present my code for telescopes can be switched between RT-Linux and
RTAI. The reason for doing this is that any potential failure during an
upgrade of one system will not impinge on that night's observing as the
telescope operator can simply use the other system.

Under the terms of your license, running RT-Linux as an academic user
is allowed without any fee. What, though, of the RTAI system? Bernhard 
Kuhn recently brought up this issue and told me he had asked you and
you were OK with it ... for the sake of our admin department, though,
I need a definitive statement. As an academic user, am I still allowed
to use RTAI without a fee since RTAI is LGPL?

Second, many moons ago, RTAI was described by yourself and others as
a "non-conforming variant" where conformity was decided by a regression
test that you (or others) would provide. I don't recall ever seeing such
a regression test and so, the question is, what now is a non-conforming
variant and how does such a scheme fall into the license arena?

Finally, the book is still in progress but we will need to make a definitive
statement on such issues. The book title is "Real Time Linux Systems" and
covers all the main variants whether they use the patented process or not.
There is, however, a bias towards hard real-time variants (since such
systems can perform in soft real-time too) and several chapters show how
to program in RT-Linux *and* RTAI (without prejudice to either one).

I am open to suggestions, not including dropping all the RTAI example
code, as to how best to address this issue. Obviously, I can write that
all issues relating to licensing should be addressed to fsmlabs (and I will)
but I need to make sure that I understand license issues surrounding the book. 
The book will have a CD with all the main variants on it. Does the book 
need to be licensed?? What do I tell readers?? 

+==================================================================+
 Phil Daly, NOAO/AURA, 950 N. Cherry Avenue, Tucson AZ 85719, U S A
 E-mail: pdaly@noao.edu  V-mail: (520) 318 8438  Fax: (520) 318 8360