Ask HN: Good framebuffer interfaces for software rendering for various platforms

My goals are academic in nature. I am building a small realtime software renderer, by using as few initial abstractions as possible to draw and build. (Also taking notes profusely, and eventually write a literate programming tutorial)

Currently, I am double buffering directly into fb0, and have no problems with a RPI with linux in that regard.

I do not know how to access the screen directly on other platforms, and would love to have your inputs in that regard!