I actually asked about this on the mailing list some time ago: http://comments.gmane.org/gmane.comp.lib.judy.devel/244 http://comments.gmane.org/gmane.comp.lib.

I actually asked about this on the mailing list some time ago: http://comments.gmane.org/gmane.comp.lib.judy.devel/244 http://comments.gmane.org/gmane.comp.lib.judy.devel/244 tl;dr: patent was done for defensive reasons.