Open Sourced Swift

Now that Swift is open sourced I have a few questions about how this might change things.

Apple will continue to update Swift, so if someone changes the open source version, do we then have 2 versions of the same language and how do we control this?

Is it going to be like Linux where you add what source you want and rework it to include the changes you want? Kinda like add ons for a browser.

I've never used an open source language before that was control inside of an ide, so what happens if you use changes to what Apple offers and then Apple changes something and it no longer works? Do you wait for the author(s) to fix it?

Is there some forum where we find out what's going on with this?