Undef in XML

I am writing some code that converts a Perl HASH to XML data. I didn’t know how to write Undef in XML. It seems this is the common way to write this:

empty value:      <string />
undefined value: <string defined=”false” />
normal value:     <string>abc</string>

Because you can have empty keys perhaps “” => undef must be written like this <item key=”” defined=”false” /> ?? This rules out Undef keys but I think I can live with it.

XMPP Protocol not for sale

Last Friday Cisco announced that it has acquired Jabber for an undisclosed sum. The Jabber development team created an open-source IM and presence protocol called XMPP used by Google Talk and Gizmo. The XMPP Protocol is not for sale but Cisco for sure bought some influence here.