Open NIB File
NIB extension files are created with Apple Xcode Interface Builder.
Interface Builder is a software development application for Apple's macOS operating system.
It's part of Xcode, Apple Developer's visual developer IDE par excellence.Interface Builder allows Cocoa and Carbon developers to create interfaces for applications using a graphical user interface, making development easier.
The NIB file stores all the information needed to build a user interface, such as text fields, buttons, a window or display component, and other more interactive types of components as well.
This information stored in NIB can be composed of parameters such as location, sizes, shapes, colors, etc.
Mac OS X applications can run without the use of NIB files, but NIB files offer an advantage in that user interfaces can be developed by programming them, but Apple Xcode Interface Builder helps create user interfaces visually, such as in Android Studio or Microsoft Visual Studio.
In newer versions of Interface Builder (starting with 3), the NIB format has been replaced by the XIB extension.
NIB files store binary data, while XIB files contain text.
Therefore, NIB files should not be opened manually.