2007.07.14 08:15 "[Tiff] [ANNOUNCE]: Libtiff 4.0.0alpha released", by Andrey Kiselev

2007.07.16 12:01 "Re: [Tiff] [ANNOUNCE]: Libtiff 4.0.0alpha released", by Ron

On Mon, Jul 16, 2007 at 10:04:20AM +0100, Andy Cave wrote:

So what happens if someone builds a standalone piece of s/w (tiffjbigdecomp) that reads (compressed) data from stdin and writes (uncompressed) data to stdout. They can then write s/w that execs a sub-process, redirecting stdin/stdout to be a file on disk and a pipe, and then just read the decompressed data from the pipe. Does that infringe GPL? I think not (as otherwise no commercial s/w could run on Linux), in which case I think the claim that dynamic loading / linking does (infringe GPL) is not necessarily solid, as the difference between that and dynamic linking to a library is pretty thin.

I think Graeme covered the technical weaseling angle. It doesn't matter how you twist and turn the bits, if at the end your work is derived from some GPL code (ie. it will stop doing something it claims to do if you take that GPL code away), then its a derived work and subject to the licence conditions for such works.

The GPL itself explains the difference to aggregated works, and the exceptions for OS components. There is no paradox here, you _can_ develop, run, buy and sell, commercial software on Linux, even the closed source variety, but you still can't weasel out of the GPL if you build on code released under it.

There are plenty of free legal forums where people can discuss this if they feel the need, but the key points here are:

All we need to figure out here is the technical details of letting people choose.