(require mzscheme) ; promise we won't redefine mzscheme bindings

   (require "ac.scm") 
   (require "brackets.scm")
   (use-bracket-readtable)

   (parameterize ((current-directory (current-load-relative-directory)))
     (load "compiled/arc_arc_scm.zo")  
    ; yeah, should chdir to ./compiled/ directly, but don't want 
    ; to fight w/ MzScheme now. And yeah, the filenames are dirty
     (load "compiled/strings_arc_scm.zo")
    ; (load "compiled/pprint_arc_scm.zo")
    ; Commented, 'cause bug in mzc or smthg (at least on my machine):
    ; compiled/pprint_arc_scm.zo::2989: read (compiled): ill-formed code [...]
    ;
    ; (aload "pprint.arc")  
    ; ^ and this commented 'cause it'd make `arc' take more than 1s, + unused by me.
    ; Uncomment if you need it, my machine is an eeePC, so on a Core 2 Duo
    ; or the like, I suppose you'll still be under 1 sec. No cheat here
     (load "compiled/code_arc_scm.zo")
     (load "compiled/html_arc_scm.zo")
     (load "compiled/srv_arc_scm.zo")
     (load "compiled/app_arc_scm.zo")
   ; Ah yeah, and I don't load prompt.arc, since a long time, useless to me.
   ; Add it here and in alc.pl, loading it will not kill perf I think (loading
   ; bytecode is fucking fast on this fucking good MzScheme).
   )

   (let ((args (vector->list (current-command-line-arguments))))
     (if (not (empty? args))  ; cmdline args are script filenames
         (for-each (lambda (f) (if (string=? f "-") (tl) (aload f))) args)
         (tl)))

   [...]
   (if (eof-object? expr)
     (when interactive? (display "(quit)") (newline))
     (if (eqv? expr ':a)
       'done
       (let ((val (arc-eval expr)))
    [...]

arc(.sh):

   #!/bin/sh

   ## arc: launcher for Arc. Put in your $PATH.

   ARC_DIR="/home/paul/arc/3.1/"  # change this

   alc.pl $ARC_DIR;
   rlwrap mzscheme -qr ${ARC_DIR}as-fast.scm $@

Note all of this is not dependant of my previous patch to make Arc OK on Unix, but you'll have to change some things by yourself if you don't use this patch.

Note 1 sec is still very long. Compare to the 0.012 secs of alc.pl.

There is this quote "On the Internet, if it's not instant, it's too long." Well, it's true in computing in general. I still have to wait before the Arc prompt to show, and this sucks.