plist

Plist, short for property list, is a structured data representation used by Apple operating systems to store serialized objects. Property lists are commonly saved as XML text or in a compact binary form, both with the .plist extension. The format originated in NeXTSTEP and became a standard data store in macOS and iOS.

A plist can hold a variety of data types, including strings, numbers (integers and reals), booleans, dates, binary data, arrays, and dictionaries. The root object is often a dictionary, which contains key-value pairs, but the top-level object can be an array or other plist-supported type. Dictionaries map string keys to values, allowing nested structures to describe complex configurations.

Common uses include storing application configuration and user preferences, as well as metadata for applications. In macOS and iOS apps, Info.plist files describe bundle information such as identifiers, version numbers, capabilities, and runtime requirements. System components and launch services also rely on plist files for configuration.

Editing and tooling: developers edit plists with Xcode’s built-in editor or third-party editors. Command-line tools like plutil can validate and convert between XML and binary formats, while PlistBuddy offers programmatic access. In many languages, libraries such as plistlib (Python) enable reading and writing plist data.

While primarily a Apple-centric format, plist files are widely used within Apple ecosystems for configuration and distribution. They are not generally intended for cross-platform interchange, though some third-party tools provide parsing capabilities for other environments.