Squirrel

The engine provides a configurable input method framework for Chinese and other scripts, supporting a wide range of schemata such as phonetic, shape‑based, and specialized layouts. Users can switch between schemes like Pinyin, Zhuyin, Cangjie, Wubi, and many regional or historical phonetics via a shortcut (Ctrl+` or F4), and adjust common options through a built‑in menu.

It runs on macOS 13.0+ (core macOS build) and is also available for Windows, Linux (IBus, Fcitx), and iOS, offering a unified experience across platforms. The project is open source, encouraging developers to study its implementation, modify the code, and contribute extensions or improvements.

Targeted at typists, language enthusiasts, and developers who need a flexible, extensible input method, the engine emphasizes custom schema design and community‑driven enhancement while maintaining a stable release status.