Joker is used to export xnu kernel's syscall symbols. The original image which running on OSX can be found at "Downloads" of URL: http://newosxbook.com/
This project is just the cloned version for joker, which can works on Windows. And the IDA plugin is used to free our hand by adding those symbols automatically.
The code is build on Mingw which IDA SDK 6.6 Relased binarys test on iOS 6.1.6's kernel (aka. xnu-2107.7.55.2.2).