I’m shocked that I actually recognize the references in an esoteric post.

Knulli - custom firmware for certain retro video game emulation devices

Anbernic - a currently popular manufacturer of said devices

Romm - self hosted software for gathering data about and organizing game roms (hence the post here)

Syncthing wouldn’t be possible to install on the stock firmware of their device, but it is with custom firmware like Knulli.