Most recently I have used zig for:
Linux USB driver for a proprietary industrial digital camera that claude hacked the protocol for (I usbpcap'ped it), bound into an embedded Elixir-Nerves biology workstation. Same workstation has a libtoupcap digital camera for a microscope camera also mounted (here I use zig for the dlload boundary with elixir). The proprietary system I am running it on ironically won't work with windows anymore because the proprietary software it shipped with chokes when there are two cameras attached.
I ship zigler, the embed-zig-in-elixir library. I keep finding more and more uses for it!