Z:gnu-www-ja-license-list--7f556d-This is a free software licens/en

This is a free software license. By itself, it has a copyleft comparable to the GPL's, and incompatible with it. However, it gives recipients ways to relicense the work under the terms of other selected licenses, and some of those&mdash;the Eclipse Public License and the Common Public License in particular&mdash;only provide a weaker copyleft. Thus, developers can't rely on this license to provide a strong copyleft.