Small GUI example using Steel Bank Common Lisp, Quicklisp, CommonQt, and Qt4.

hello-qt.lisp

#!/usr/bin/sbcl --script

; Also see http://pleasegodno.wordpress.com/common-lisp-tutorials/common-lisp-gui-programming-with-commonqt/introduction-to-commonqt/
; or see http://kvardek-du.kerno.org/2011/12/setting-up-commonqt-on-osx.html if you're still using Mac OS

(let ((quicklisp-init (merge-pathnames "quicklisp/setup.lisp"
                                       (user-homedir-pathname))))
  (when (probe-file quicklisp-init)
    (load quicklisp-init)))

(ql:quickload 'qt)

(defpackage :hello-qt
  (:use :cl :qt)
  (:export #:main))

(in-package :hello-qt)
(named-readtables:in-readtable :qt)

;;;;Hello Qt

(defun hello-qt()
    (let* ((app (make-qapplication))
           (label (#_new QLabel "<strong>Hello Qt!</strong>")))
        (#_setWindowTitle label "Hello, Qt!")
        (#_resize label 100 100)
        (#_show label)
        (unwind-protect
            (#_exec app)
        (#_hide label))))
(hello-qt)