Swift was initially released in 2014 and has seen annual updates with new versions released. The updates have included new features, performance enhancements, and bug fixes. While Swift code can interoperate with Objective-C code, interacting with Objective-C classes and objects from Swift requires bridging as Swift uses its own types and paradigms instead of being a strict superset of Objective-C like other Apple languages. Testing and mocking functionality in Swift has also continued to evolve and improve with new features added over time.