Eckhart Wörner wrote: [snip]
The Problem is the Licence: the function is licenced under the GPL, this means, that my 'derivative work' has to be licenced under the GPL, too.
That's right -- it's a "share-alike" license.
Well, I thought of publishing the source code, too, but I'm more a fan of the Creative Commons licences (http://creativecommons.org/licenses/by/2.0/de/ in this case, to be precise). But this creates trouble with the GPL, which makes it impossible to use the CC licence.
Creative Commons licenses aren't really meant for code. Please see the FAQ: http://creativecommons.org/faq#faq_entry_3646
"Can I use a Creative Commons license for software?
In theory, yes, but it is not in your best interest. We strongly encourage you to use one of the very good software licenses available today. (The Free Software Foundation and the Open Source Initiative stand out as resources for such licenses.) Unlike our licenses -- which do not make mention of source or object code -- these existing licenses were designed specifically for use with software."
CC has a license discussion list which might be a better place to ask these kinds of licensing questions: http://creativecommons.org/discuss
-- brion vibber (brion @ pobox.com)