.eimformat. This is an executable that contains your signal processing and ML code, compiled with optimizations for your processor or GPU (e.g. NEON instructions on ARM cores) plus a very simple IPC layer (over a Unix socket). We do this because your model file is now completely self-contained, it does not depend on anything (except glibc) and thus you don't need specific TensorFlow versions, avoid Python dependency hell, and will never have to worry about why you're not running at full native speed.
.eimfiles using the Edge Impulse for Linux CLI or from the Studio (go to Dashboard, then enable 'Show Linux deploy options', and they'll be listed under Deployment). You can also build the
.eimfiles yourself with the Edge Impulse for Linux C++ SDK, see Building .eim files.