Comment 367 for bug 269656

Here's Mozilla's licensing page:

"Acceptable Licenses

   1.

      The following license (the "Mozilla tri-license") is acceptable in all circumstances except for those covered by point 4, below:
          * MPL/GPL/LGPL triple license, allowing use of the file under the terms of any one of:
                o The Mozilla Public License, version 1.1 or later (MPL)
                o The GNU General Public License, version 2 or later (GPL)
                o The GNU Lesser General Public License, version 2.1 or later (LGP...

3. The following licenses are acceptable only for Support Code in directories whose files are already under the license in question, as outlined later in this policy:

    * The Mozilla Public License, version 1.1 or later (MPL) alone
    * The Netscape Public License, version 1.1 or later (NPL) alone
    * MPL/GPL dual license, allowing use of the file under the terms of either of:
          o The Mozilla Public License, version 1.1 or later (MPL)
          o The GNU General Public License, version 2 or later (GPL) ...

3. All Product Code must be under either the tri-license or, for Third Party Product Code, a license compatible with all three sets of terms in the tri-license. The purpose of this rule is to make sure that users of our code can take and use the same code under any one of the three licenses; no group is disadvantaged."

http://www.mozilla.org/MPL/license-policy.html