Just clang on my system is around 80MB, so when you consider that an SBCL image includes a compiler, a linker, and a loader—and if you have Quicklisp installed, a build system and a package manager—40MB starts to look like a bargain!
I personally wonder if CL's "computer program as an image" instead of the Unix process-oriented architecture will see a comeback in this modern era of virtualization and rump kernels and containers. In theory a Docker image for an SBCL program would be just the Lisp image itself plus the small handful of standard POSIX libraries on which the Linux version of SBCL depends (e.g., libc, libm, libpthread, etc.)
I personally wonder if CL's "computer program as an image" instead of the Unix process-oriented architecture will see a comeback in this modern era of virtualization and rump kernels and containers. In theory a Docker image for an SBCL program would be just the Lisp image itself plus the small handful of standard POSIX libraries on which the Linux version of SBCL depends (e.g., libc, libm, libpthread, etc.)