Pandu Poluan wrote:

The easy way would be for foo to use clamscan, or clamd. If the GPL code lives at a different process, foo don't need to be GPL. http://www.gnu.org/licenses/gpl-faq.html#MereAggregation A way to weaken the would be to allow different libs to improve to your otherwise full foo program by foo exposing different interfaces to them. So you would be using a GPL-plugin for foo, using genereic, documented, interfaces (not written specifically for clamav!). That might stand if it was done by an independent third party (unrelated to foo or clamav) not interested on having it other than using the great features of foo and clamav combined. But if you're developing foo you should probably gpl-license foo. And if you were developing clamav you should probably provide an exception for linking to foo http://www.gnu.org/licenses/gpl-faq.html#GPLPluginsInNF http://www.gnu.org/licenses/gpl-faq.html#LinkingOverControlledInterface In the hypothetical case i mentioned, when you can't change the rights of any of the parties, i find odd that you couldn't do that, but GPL was made with its viric nature in mind. Nonetheless, IANAL, so take my 2 cents with care. :-)