--------------------[ LISP dialects & package systems ]--------------------

I like GCL a lot---its command line's tab completion and line-editing
are convenient, it installs on Linux or MacPorts with a single command,
and I wrote my very first Rubik's cube solver in it :) However, its
development has somewhat fallen behind, and other implementations of
Common Lisp overtook it. In turn, package repositories preferred
these other implementations.

These days, a language does not end with a compiler/interpreter and a
runtime---programmers expect a centralized package repository with a
large number of packages for all kinds of purposes, from which they
could get a needed package with a single command. Perl's success
was largely due to CPAN.org, and Python, Ruby, and other languages
followed (although their package managers have become fragmented,
and "install this package manager to install this package manager"
is confusing: I like being able to read the code of my package mamager!)

Modern LISPs now also have their own repository and package manager,
Quicklisp. Unfortunately, it does not support GCL. Luckily, MacPorts
has (at least) two LISP implementations Quicklisp supports: Steel Bank
Common Lisp (SBCL) and Clozure Common Lisp (CCL; no relation to Clojure
the language).

I installed SBCL ("port install sbcl"). SBCL's command line is primitive:
out of the box, it does not support either tab completion or line editing
(pressing arrow keys gets you weird characters). Luckily, there's a package
for that that can be downloaded with Quicklisp---which is why you saw
my command line being even nicer than GCL's.

My installation log is in  sbcl-quicklisp-install-log.txt

A jargon note: in Quicklisp, packages are called "systems". This
probably reflect the fact that they get installed with all dependecies
automatically tracked (by a subsystem called ASDF).

If you use MacOS, you could also try advice in
  http://www.jonathanfischer.net/modern-common-lisp-on-osx/