We’re going to create a "swift-3.0-branch" branch across the various Swift repositories within the next couple days. The branch will be used to provide a more stable baseline for producing qualified snapshots for Swift 3. With a large number of Swift 3 changes having landed the idea is to provide more qualified downloads — probably called “developer previews” or something of that nature — that will be available for those interested in playing with Swift 3 but not wanting to pull just the latest snapshots from master. I’ll post details on how this branch will be managed via a blog post in the next couple days. For the time being, you can just ignore it — but I wanted to give everyone a heads up on why it was there.