I noticed something today while exploring KisKis - Keep It Secret! Keep It Safe!, a free-as-in-speech (GPL) password manager written in Java. KisKis can export and import the passwords in XML using dom4j. The problem is MetaStuff publishes dom4j under an unmodified BSD license that is incompatible with the GPL due to the advertising clause. Unless the dom4j folks are willing to change their license to remove the advertising clause, free-as-in-speech products should avoid it. XOM, JDOM, DOM, and SAX, by contrast, are all GPL-compatible. I just spent a lot of time over the last few months getting the advertising clause removed from the Jaxen license, so this is very much on my mind right now.
