The people over at StabbilityAI released the model as an OpenRAIL license. They do charge on their own site for renders but that's for GPU time.
https://stability.ai/blog/stable-diffusion-public-release
My RTX 3070 with 8GB for VRAM can only do 512X512 max.
Grisk create a front end for the model and packaged everything up for us.