Where is the arduino core?

On this page https://www.crowdsupply.com/sifive/hifive1 it says Arduino IDE support.

I was wondering if you had an arduino software core available. Where can I find it? I see there is an sdk on github with makefile/gcc examples. Maybe I am just not looking in the right place which is why I am asking here.

Can you confirm if it is closed development or planned development?

We will be releasing the open-source Arduino board package within the next few days. Please stay tuned!