These demos demonstrate using Gtk directly from a higher level language.
None of the demos have any low level code in them.  There is no need for
any makefiles, C compilers, or any other low level stuff.  There is
probably no need to install Gtk, because it's probably already used by
your Linux.

To use a different high level language for these demos, it is of course
necessary to edit them to change the language.  But they aren't very long
and that might not take very long.  It's strongly advised to run the
present demos first, and make some minor changes to them, to see the
differences, to make sure to understand how they work, before starting to
change them to a different language.

When a demo script gets invoked, the code gets compiled into memory, with
a very fast compiler, so there will be no object files, executable binaries,
etc., unless those are desired.  The only requirement is to download or copy
and paste the demos and demostuff and make each demo executable with
"chmod +x demo".  Then run the demos with "./demo1 ; ./demo2 ; ./demo3".

If there are error messages about not finding sbcl, it might be necessary
to install that, or to add it to the path.  Installing sbcl is easy, usually
via the Linux distro.

In the rare circumstance that a particular Linux distro doesn't have sbcl,
you could install a binary version from Sourceforge:
prdownloads.sourceforge.net/sbcl/sbcl-1.4.14-x86-64-linux-binary.tar.bz2
or, if desired, you could compile it from sources from sbcl.org.