Apple has excellent design credentials. They make things smooth. Apparently they sat back, took their time, learned the lessons from other programming languages out there and when the time was right, make a smooth programming language. Now, you will be able to use Apple Swift everywhere. Read the article on Wired as it lays out the strategic overview.
By setting Swift as open source it has gained prominent status among software languages. The old open source strategy is in effect, wide open specification, reference architecture, compete on implementation. Apple announces the plans on their blog and the plan is good. As I estimate, by sometime in 2016, you’ll be able to use Linux as a launch point for building Apps that work there, on Apple OS, iOS and perhaps beyond. That then brings us to the choice of programming languages in the near future.
An intense choice may then arise between Java, C#, Swift, and C++ in the area of cross-platform user interfaces. See the Wired article for indirect discussion of the first 3. Swift will continue to surge but to a greater magnitude as Apple sustains and greatly expands its place as the leading user interface platform. Of course, C++ is a sure thing but the opposite of smooth. Meanwhile, the large base of existing practitioners in C# will make for an interesting technology decision matrix.
What might the future look like? As you get closer to the year 2020, user interfaces written in Swift, Apple as the leading platform for mobile, wearables, and solid midsize computers. Web applications and server code written in PHP, Google Go, or C#. Systems code and ultra optimized processing will continue to be written in C and C++ with Mozilla Rust potentially replacing Java in heavier back-end work. No one language to do it all except C and C++.
The Swift language may edge into these other areas depending on how Apple engineers future versions of the language. As stated, it is designed to replace C and the first target is user interfaces. However it goes, the saga will be interesting.
Original Source Quora | What will it mean in practice that Swift is open source?