Renderer backends

[lookeypl]

This task is a mega-task, which is only a pass-through to navigate to our Renderer progress spreadsheet.

https://docs.google.com/spreadsheets/d/1Kl3_I9YdRSvWKjz-bxoUPqlyoaC7tmRHKzNL0_X7MZs/edit#gid=0

To be closed when everything above will be finished at 100%.