With SBCL and Linux kernels with binfmt_misc support enabled (module or compiled) you can execute FASL file from command line, using the same SBCL core for all the executables and, I would add, with an "instantaneous" feel. ^__^

With Debian it should work out of the box, on other distributions it probably needs to register a wrapper/trampoline with the binfmt_misc infrastructure.

FWIK running instances don't share the same core in RAM though.

  $ cat hello-world.lisp                                                     /tmp
  (print "Hello. World!")
  $ sbcl --noinform                                                          /tmp
  * (compile-file "hello-world.lisp" :output-file "hello-world")
  ; compiling file "/tmp/hello-world.lisp" (written 23 AUG 2017 11:09:24 AM):
  ; compiling (PRINT "Hello. World!")
  ; /tmp/hello-world.fasl written
  ; compilation finished in 0:00:00.001
  #P"/tmp/hello-world.fasl"
  NIL
  NIL
  * %                                                         
  $ chmod +x ./hello-world.fasl                                              /tmp
  $ ls -lh hello-world.fasl                                                  /tmp
  -rwxr-xr-x 1 user user 330 Aug 23 11:17 hello-world.fasl*
  $ time ./hello-world.fasl                                                  /tmp

  "Hello. World!" ./hello-world.fasl  0.00s user 0.00s system 44% cpu 0.009 total
  $                                                                          /tmp

Edit for clarifications and fixing formatting