On viral licenses

While trying to find a workaround for a bug in a commercial closed-source application, running strings on one of the binaries revealed some strings that obviously came from an open-source project. This project was dually licensed (GPL/MPL).

On July 17th I sent the following e-mail to the authors of the open-source project (names withheld for now):

Date: Thu, 17 Jul 2003 16:46:36 +0200
From: Peter van Dijk <peter@dataloss.nl>
To: X1@X2.com
Subject: commercial usage of X3
User-Agent: Mutt/1.4i

Hi,

working on a bug in a X4-application we bought, I noticed strings
from the X3 source (notably
'X5').

The piece of software in question is X6, the binary
is named 'X7'.

If you did not know about this, you might want to check whether they
are using your code legally. Their product is not opensource.

Their website is at http://www.X8.com/

Greetz, Peter

I got the following reply the next day:

Delivered-To: peter@dataloss.nl
Date: Fri, 18 Jul 2003 10:10:25 +0200
From: XX <X1@X2>
To: Peter van Dijk <peter@dataloss.nl>
CC: X1@X2.com
Subject: Re: commercial usage of X3
In-Reply-To: <20030717144636.GB12633@dataloss.nl>

Hi Peter,

Thanks for the information. We will check it.
X9

So right now I'm waiting and wondering. I withheld names for now because I could be wrong -- these people may be using this code legally, either because I misread a license, or because they obtained a separate one, or some other reason I don't think of.