SWIFT, Swift Source Code File (.swift)
The SWIFT Developer file format
SWIFT files contain source code written in an Apple native programming language of the same name. This relatively new programming language was introduced in the OS X version Yosemite and, respectively, iOS 8. Files that have a SWIFT extension are used to write and compile apps for apple devices such as the iPad, iPod, iPhone or Mac computers.
Technical details of SWIFT files
The code contained in the SWIFT file is written and saved in a plain text format. The versatile SWIFT programming language can be compared to the style of Objective-C developer languages. Yet, the language as well as the SWIFT file offer different and advanced features like an automatized memory management. Furthermore, it allows the integration of other frameworks like Cocoa.