This bummed me out, but it looks like it's not? From the Sunshine (server) GitHub page[1]:

  Sunshine is a self-hosted game stream host for Moonlight. Offering low latency, cloud gaming server capabilities with support for AMD, Intel, and Nvidia GPUs for hardware encoding. Software encoding is also available.

1: https://github.com/LizardByte/Sunshine

I think it was originally all NVIDIA proprietary, then got reverse engineered OSS client(Moonlight), then got RE'd OSS server(Sunshine).

I have it running clean and crisp hosted off an old i5 SFF HP G2 mini slice with integrated Intel graphics so give it a try!