Re: embedded emc and GPL

[Paul <paul.corner-at-tesco.net>]

Hi Markus

The GPL license does not in any way restrict a commercial use of GPL'd 
software. If you read the terms, it quite clearly states that you are free to 
modify and redistribute any derived works for any fee - As long as you give 
the customer access to the source code. The one thing you may not do is claim 
copyright or change the terms of the license.
EMC it's self (as opposed to some of the G-code files and Tcl/Tk routines) is 
not subject to copyrights or GPL licenses. According to emails from June/July 
2000, you may do as you please with the sources. Hack, modify, port to other 
platforms, etc, etc. The ONLY restiction is that you may not claim copyright 
yourself.

Public domain software on the other hand often has restrictions attached. 
Either the sources are not available, or some limits are placed on it's use. 
More often than not, each piece of PD software had to be examined for the 
exact terms of the license.

Regards, Paul



On Monday 04 Mar 2002 8:35 pm, Markus Meyer wrote:
> Hi Pete,
>
> I'm afraid I didn't really understand what your original question was, but
> as far as the GPL is concerned, I see two "problems" with using it:
>
> 1. Since the GPL includes a copyright claim, it's not that easy to change
> license from public domain to GPL. Furthermore, GPL places some
> restrictions on code (re-)use, and IMHO that would not comply with the
> original public domain style.
>
> 2. The big "problem" with the GPL is, that it limits commercial use by
> explicitely stating, that a software derived from a GPLed software must be
> GPLed, too. GPL-enthusiasts take that "derived work" term very seriously,
> it holds, even if the amount of GPL code used is very small compared to the
> size of the "derived" program. So, consider, EMC would be GPL. If you only
> take a few lines from the original code (f.e. the G-Code interpreter) and
> build it into your own software, you had to make your whole software GPL,
> too. One may find that good or bad (Personally, I find this policy just as
> extreme as software patents, in a certain sense). But I'm sure that this
> would scare many potential EMC users and resellers.
>
>
> Best regards
>
>
> Markus