I'm the author of a small-fish webmail package called IlohaMail, and I've been wondering if there were licenses like GPL that applied better to PHP-based applications that don't have binary distributions. Personally, I think deployment of web-apps is more or less analogous to distributing binaries (they're both acts of making software available for use by others), however, under the GPL, we're not offered the same kind of protection.
For example, my app has a link to the project website in the login page, and it's the only place where there's any branding in the whole interface. One thing I've noticed is that some organizations deploy my software without the link that goes back to the project website, which I think is a lot like redistributing software under a different brand (after all, for all the users know, what they're using isn't IlohaMail, but a software their organization wrote). Under the GPL, a vendor who redistributes a rebranded product is required to make the altered source code available, however, an organization that deploys modified web-apps is not required to make the source code available.
Furthermore, I think there are actually real damages to us because of this. If organizations that deploy modified versions of web-apps were required to make their source code available to the public, I think there's a good chance that some of them would prefer to pay for an alternative license that exhempts them from this requirement. In other words, because PHP-based scripts really aren't covered by the GPL, we're losing a potential revenue source.
What do others think about this? Is it just me, or does it concern anyone else? Is there a better license out there, or perhaps one could be created?