Before using POK, you MUST read the licence of POK. If you disagree with the licence, you MUST NOT use POK. By downloading and using POK, you are engaged to respect the licence.
Public snapshots can be found on http://download.tuxfamily.org/pok/. There is no official release at this time.
The repository can be found on github at https://github.com/pok-kernel/pok
A toolchain is available to use POK on Windows. The toolchain is available on http://download.tuxfamily.org/pok/(pok-toolchain-windows.zip). It is still in beta test, do not hesitate to provide your own experience using this toolchain.
Other support host development (Mac OS X, Linux) don't need a dedicated toolchain. To get more information about required tools, refer to the documentation and installation notes.