[quote name='mdwh' timestamp='1325254932' post='4898136']
All licences (including proprietary) are "viral" in the sense that if you distribute someone else's code in your product, your product has to abide by any of those licences.

When people say that the GPL is "viral" they refer to the 5.c clause;[/quote]I know about the GPL; yes there are terms to abide to for your work. People mean many things by "viral", but sometimes I see it (not meaning you meant it this way) being meant in a negative way, when proprietary licences apply restrictions also. Yes, it's an interesting way to look at it that you pay for it by way of open sourcing your code too, though I wouldn't call that viral myself.