Personally, I think a tightly defined 'download button' is a rather awkward method to enforce copyleft for webservices. I would prefer more generic terms, such as the following license clause (which uses the term 'public display' rather than 'webservice' in an attempt to generalize the clause as much as possible):
"Public display of the Software is allowed, provided that You ensure that all users are also able to receive the complete Source Code of the Software by means of a medium custorarily used for software interchange, without any charge beyond the costs of data transfer, and present a prominent notice to the users explaining this." I'm not sure whether the term 'public display' is indeed suitable for this purpose, but the clause could easily be altered to cover 'software that is intended to interact with users through a computer network' (conveniently taken from the Affero GPL) if necessary. The proposed clause doesn't place any restrictions to the form and technology other than requiring a 'prominent notice'. Even though 'prominent' hasn't been defined explicitely, the spirit of this license term is quite clear IMHO, and purposely hiding the download information in some obscure corner of the webservice clearly doesn't follow this spirit. Of course, IANAL etc. Regards, Marc Rauw. -- license-discuss archive is at http://crynwr.com/cgi-bin/ezmlm-cgi?3
