Disclaimer: I am not a lawyer.
I have no idea why, but this question has come up in several different emails to the “license at eclipse.org” mail id this week. Maybe it’s because of Sun’s recent announcement that it was releasing Java under the GPL. The question has been asked in several different ways, but the short version is: “my lawyers tell me that the Eclipse Public License is just the same at the GNU Public License. So the EPL is a viral license, right?“
No it’s not.
First of all, what does the term “viral” mean? The Free Software Foundation folks quite justifiably do not like that pejorative term, but many people use it to refer to the provisions in the GPL which require programs that link to GPL code to in turn be distributed under the GPL. That is not true of the EPL, which expressly allows you to distribute your own code combined with EPL code under your own terms and conditions (subject to the limitations of the EPL etc. etc. etc.).
It is true to say that the EPL is a copyleft license, so in that way it is similar to the GPL. But that doesn’t make it “viral”.
It really depends how you evaluate the attributes of the various licenses, and I’ve personally seen many different ways to do this. In some taxonomies, the “copyleft” attribute and the “viral” attribute are separate. In other taxonomies they are combined. It’s likely reasonable to say that the EPL is “copyleft, non-viral”.
But to claim that the EPL is just like the GPL is going over the top. And to claim that the EPL is viral is just wrong, at least when using the common definition of viral.