Experimental Physics and
Industrial Control System

"Konrad, Martin" <[email protected]> · Wed, 22 Oct 2014 21:21:39 +0000

Hi Emmanuel,
> Who comes up with those licenses?
Lawyers do since they are paid to ensure that the authors do not run
into any legal risks by publishing their software.

> The enforcement is key. The GPL means the author of the original
> software wants to promote the ideology of forever free open source
> software.
Note that it is a right of the author/employer to decide which 
privileges he grants to others. We should be grateful that he decided to 
share the code with us in the first place (even if you are not allowed 
to do whatever you like to do with it). Also note that advocates of the 
strong copy-left say that GPL grants users _more_ privileges than most 
other licenses (it intends to increase the rights users have if you look 
at the bigger picture).

But you're right, there are many practical issues with GPL's
compatibility to other licenses. That's one of the main reasons why a
lot of the EPICS community's code is _not_ covered by GPL but by 
licenses without strong copy-left.

BTW: Most of the OSS developed today is written by professionals not
enthusiasts. This has a significant impact on the way a license is chosen.

> In theory, a private (US?) company could come, take the software,
> modify it, close the source, and resell it. Of course, that's not the
> case with the GPL.
Yes, it is. Everyone can take a piece of GPL software, modify it and 
sell it to a customer [1]. You are _not_ forced to share it with the 
world [2]. But you _do_ need to share the source code with your customer 
if you ship him the binaries. And of course you are also allowed to 
charge for SaaS (e.g. cloud-based products) without sharing 
binaries/source code.

A way around license compatibility issues might be to contact the author 
of the code and convince him to dual-license his code. He might be 
willing to do that only if you pay a license fee, though.

> The GPL is regarded as business unfriendly as it removes FOREVER a
> major revenue stream.
You are allowed to sell GPL software for money, you are not forced to 
share your source code with the world (if you don't share the binary 
with the world) and you are even allowed to develop a modified version 
for a customer under NDA [3]. That's enough for many companies to 
generate revenue. Of course OSS requires a bit different business model 
than selling proprietary software but you can still generate revenue 
(Cosylab for example does).

Regards,

Martin

[1] http://www.gnu.org/licenses/gpl-faq.html#DoesTheGPLAllowMoney
[2] 
http://www.gnu.org/licenses/gpl-faq.html#DoesTheGPLRequireAvailabilityToPublic
[3] http://www.gnu.org/licenses/gpl-faq.html#DevelopChangesUnderNDA

-- 
Martin Konrad
Control System Engineer
Facility for Rare Isotope Beams
Michigan State University
640 South Shaw Lane
East Lansing, MI 48824-1321, USA
Tel. 517-908-7253
Email: [email protected]

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System