Igniters, Normally we are trying to maintain backward compatibility with previous versions. But it is not always possible.
E.g. we are about to release portable protocol. There are lots suggestions how to optimize it, but all of them are relatively hard to implement. It would not be a problem if are able to improve it iteratively from release to release while still allowing for different versions (e.g. 1.5 and 1.6) to communicate. What if we add a top-level property "*compatibility level*" allowing user to "downgrade" some parts of the system to communicate with earlier versions? Vladimir.
