yabai started as a C99 rewrite of chunkwm, originally supposed to be its first RC version.
However due to major architectural changes, supported systems, and changes to functionality, it is being released separately. There are multiple reasons behind these changes, based on the experience I've gained through experimenting with, designing, and using both kwm and chunkwm. Some of these changes are performance related while other changes have been made to keep the user experience simple and more complete, attempts to achieve a seamless integration with the operating system (when possible), proper error reporting, and yet still keep the property of being customizable.
Requirements... More Info »
yabai is officially supported on macOS High Sierra 10.13.6 and macOS Mojave 10.14.4/5. It uses a scripting-addition, which is a bundle of code that we inject into Dock.app to elevate our privileges when communicating with the WindowServer. The WindowServer is a single point of contact for all applications. It is central to the implementation of the GUI frameworks and many other services. Because of this, System Integrity Protection must be disabled for yabai to function properly.