Attached is an implementation for SBCL. make-static-vector only allocates instances of (simple-array (unsigned-byte 8) (*)) but that can be extended to other unboxed arrays. The current sharable vector interface doesn't work very well because it doesn't allow me for instance to pin a list of vectors, but only a single vector at a time. Also, I'd prefer to avoid pinning at all given how it interferes with the GC.