Objective-C

Objective-C is a legacy programming language that served as Apple’s primary language for iOS and macOS development before Swift. It extends the C language with object-oriented features and relies on Smalltalk-style messaging for method calls.

Developers used Objective-C with Xcode to build applications using Cocoa and Cocoa Touch frameworks. Though now largely replaced by Swift, many legacy apps and systems still run on Objective-C. It supports dynamic typing, runtime introspection, and categories, giving developers flexibility in building modular applications.

Objective-C integrates tightly with Apple’s native APIs and remains compatible with Swift for mixed-language projects. It’s still supported by Apple and used for maintaining or upgrading older codebases. Objective-C played a key role in the early success of iOS development and influenced many modern languages.