Re: [ng-spice] new guy: licensing issues


To ng-spice@ieee.ing.uniroma1.it
From Paolo Nenzi <pnenzi@ieee.ing.uniroma1.it>
Date Tue, 11 Jan 2000 09:16:31 +0100 (CET)
Delivered-To mailing list ng-spice@ieee.ing.uniroma1.it
In-Reply-To <0001110041520N.00837@yaesu.ada-works.com >
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Reply-To ng-spice@ieee.ing.uniroma1.it



On Tue, 11 Jan 2000, Reid van Melle wrote:

> 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.
In a couple of weeks there will be an interface to browse the lists on the
web. 

> 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.
OK, I will not ask more ;-)

> 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.
That's an interesting news. If you would like to give a look to the work
done on our side (mainly) by Widolok, download ng-spice-rework-4.tar.gz
from: ftp://ieee.ing.uniroma1.it/pub/ngspice/experimental


> 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.  
They seems promising, at leat for BJT circuits.

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...
You are welcome.


> 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.  
I am not veri informed in licensing issues, I think that LGPL and GPL are
compatible. In ng-spice project (please note that the GPL version of
ng-spice is not yet developed) we think to exploit modularity. I think
that some code can be inserted as a library, thus not infinging the GPL. 
There is anyone on this list with knowledge on the subject that can help
us with that ?

 

> 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).
Can you explain better ?

> 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.
Well, this is what we have in mind, to build a software that gets its
roots in the past experience in circuit simulation, taking only the good
pieces and modifying the bad ones. Compatibility with existing software is
an issue, there are too many spice netlists around. I think that moving
to HSPICE compatibility will be good, as this product is rated as the
best circuit simulator (or one of the bests).

Bye,
Paolo Nenzi


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