Hi Hannes,
On Tuesday 06 September 2011 13:09:31 Hannes Hauswedell wrote:
First and foremost it has to be Free
Software[link to our definition]. This includes -- but is not limited to -- the software component responsible for rendering the PDF (e.g. Skim[link] does not qualify, because it uses a proprietary library for PDF rendering).
In our technical definition we should make clear that we mean "additional" libraries for proprieary systems. Check out the Gnu GPL line on this., The components that normally come with _all_ versions of a proprietary operating systems can be used by Free Software on it, even with the GNU GPL. We should not get stronger than this.
We are stronger than this, because we are about Free PDF-Readers.
..then the above explanation of the criteria should be improved.
A software using a proprietary pdf-rendering library which comes with all versions of the operating system is Free Software to begin with, so it matches our Free Software definition I guess. Also requiring the pdf-render library to be Free Software means is another requirement and you need a definition what is the render library. Does it for instance include support library for the rendering, e.g. like an XML library that might come from the system? If so, why?
I don't know what library Skim uses so I cannot say, but the criteria should be understandable, otherwise people will rule out all pdf readers on proprietary platforms. They all use proprietary libraries at least some.
Yes, but these libraries can be replaced.
All proprietary libraries can be replaced. If you apply this thinking you'll end up without any Free Software reader on proprietary platforms. Which is not what I believe is sensible.
E.G. Okular on Windows might link against some Windows libs, but the same piece of source-code will produce the same piece of software on a completely free system.
Every library can change behavioural details, so it will not behave similiar on GNU systems. Almost all GNU systems I have heard of are not entirely "free" either, many use proprietary BIOS, firmware or microcode on their chips. Any of these components will change the behaviour of the software. If you come up with such a criteria it should be sound.
With Skim this is not the case. Skim uses PDFKit which is installed on every MacOSX and cannot be removed, but there is no gain in Freedom for the user, because *all* functionality depends on this proprietary lib.
That is a good reason to demand that Skim is not listed, I agree.
Needless to say you cannot port Skim to another (free) OS.
Sure you can, just "port" or use a different library. :P
So I think our policy is sound. We have discussed this multiple times, but of course I open for any new input on the matter :)
The proposed explanation of the policy does not explain the borders of this decision. I suggest to explain this in more detail saying that the frontend and the backend of the PDF software needs to be Free Software. And then the "backend" needs to be defined a little bit. Maybe containing the core logic of the PDF format or something.
Thanks again for working on this, I am merely trying to check if the argument on the explanation makes good sense so you are most effective in communicating this great campaign.
Best Regards, Bernhard