Swift's concurrency story is pretty much handled by GCD. IMO a fantastic set of APIs that make it pretty easy to deal with worker threads and queueing tasks and such.
The interesting part about Swift being open sourced for linux is what API's will come with it. I would not be surprised if GCD doesn't come along.
libdispatch is Apache licensed.
Ahh nice - I didn't know that. It'll still be interesting to see what happens to the rest of the libraries and API's that are common place in Swift development