new guy: licensing issues


To ng-spice@ieee.ing.uniroma1.it
From Reid van Melle <reid@ada-works.com>
Date Tue, 11 Jan 2000 00:07:11 -0600
Cc ada-devel@ada-works.com
Delivered-To mailing list ng-spice@ieee.ing.uniroma1.it
Mailing-List contact ng-spice-help@ieee.ing.uniroma1.it; run by ezmlm
Reply-To ng-spice@ieee.ing.uniroma1.it

Hello, I am new to this list and have spent the last little while downloading
the 517 messages sent since the list started and reviewing some of the
discussions etc.

I work for a company called "Analog Design Automation".  We are a fairly new
company developing analog synthesis software.  Some of the non-proprietary
information I can tell you is that we use analog circuit simulators as part of
the inner loop of some of our algorithms.

One of the simulators we are currently using is an in-house
improved/modified version of Spice3F5.  For speed and efficienty, we have
reimplemented the main() call as a function call.  The function call takes a
char* buffer with a netlist and returns a struct with the simulation
results.  One of the problems we had initially is that Spice3F5 leaked memory
faster than a water bucket with no bottom.  Therefore, we modified
the source to remove all the memory leaks.

At this point, the company is planning to have me continue development on
Spice3F5 to improve convergence using some of the published homotopy methods
etc.  However we noticed that some of the work being done on ng-spice overlaps
with our own effort.  Since we are not in the business of selling a Spice
simulator, we are perfectly willing to contribute our own development (where
relevant) to a GPL product such as ng-spice.  However, there is one problem...

Since we compile Spice into a library and then compile this into the 
commercial
version of our software, a straight GPL license will not work for us.  
Instead,
we would need a LGPL version of the software or the option to purchase a
separate commercial license.  In any case, we are interested in contributing 
to
the development of the software wherever possible and then incorporating this
into our commercial product.  It is worth mentioning that we have a version of
our software which uses a command-line (i.e. standalone) version of Spice and
would therefore be GPL compliant.  However, we would like to have a license
where we can compile it into our software since the performance gains are
significant (mainly for small circuits etc. where the overhead is large).

We find ourselves in the same situation as many companies:  the academic
version of Spice is no good and we are left with the task of modifying it to
suit our needs.  Unlike other companies, we would like to contribute to the
development of a GPL version of Spice and and take advantage of the work done
by the GPL software community.  Hopefully this would be a win-win situation.

I hope that something can be worked out and look forward to any discussion on
the list.  I emphasize that our company is NOT in the business of developing
and/or selling analog circuit simulators.  Feel free to ask me any relevant
questions.

                                Reid van Melle
                                Software Design Engineer
                                Analog Design Automation Inc.

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