Developers now have access to the first preview release branch for Swift 3.0, the next evolution of Apple's custom programming language.
"Snapshot" downloads are linked from the official Swift website. The site cautions that the snapshots aren't official releases, and hence have only gone through automated unit testing.
On the Swift GitHub page, it's also warned that 3.0 makes source-breaking changes, although in later versions the goal will be to retain as much compatibility as possible. Anything that might break source will purportedly be rolled out in "the least invasive way" possible.
Apple is likely to showcase Swift 3.0 at its annual Worldwide Developers Conference, which kicks off June 13. The language won't be finalized until sometime later this year however, presumably in time for one of Apple's regular fall press events.
The keynote will most likely concentrate on the next versions of OS X and iOS, as well as improvements to Siri and Apple Music. Apple might theoretically show off new Macs and peripherals, but the company has generally veered away from showcasing hardware at WWDC.