Reverse engineering IntegraLive
GUI-specific state data are persisted in .integra files as userData endpoints of Container and Scene nodes, in the form of XML strings. The exact structure and semantics of these data are not well documented, so writing new GUI code capable of interpreting existing .integra files with all GUI-specific state intact, and writing new files with exactly the same format (so they could be interpreted by IntegraLive v1.x), would require a substantial reverse-engineering effort---more than we have time for.
I therefore propose that we develop our own new XML format for GUI-specific data in Integra2, and forego backward compatibility. That is, we need not write XML data exactly as earlier versions of Integra Live have done.
Reading XML data from existing .integra files is a trickier question. We can certainly begin by ignoring XML entirely; it is not required for correct operation of libIntegra, except probably for switching scenes.