Ok, after bashing my head against the Spinning Wheel of Death for ages trying to use FFI to interface to the Bonjour service discovery library, I've done it another way using essentially the same design framework, but scraping the command line output from dns-sd with the help of OSSubProcess. This is on a MacOS/M1/Monterey, Pharo 10 setup. This works nicely, but I would still like to get to the bottom of why the FFI doesn't work for this. So I've made all the code available on https://github.com/StewMacLean/Bonjour. You can either download a preloaded image/changes or use Metacello to download and install into a fresh P10 image. Once downloaded, it will select the openApp for the command line interface to run. To run the library interface you need to do the same thing, in that class - please refer to the read me and browse the code. I'd really appreciate any help I can get to get this working. I think it would make a great demonstration app for FFI usage once running. Please sing out with any questions etc. Thanks! Stew MacLean