dgolden

Well, as other posters have pointed out, lisp is multiparadigm, not just functional.

Anyway your question was more about abstract concerns, but concretely, note there are pretty decent SDL and OpenGL bindings for common lisp, and mildly optimised native compiled lisp code borders on "fast enough" for fast-paced 3D games - I mean people write fun games in Python these days, never mind lisp! even if GC is not concurrent, GC pausing is much less of a problem than people make out with a little common sense and care, - prealloc object pools before levels begin, code consless or at least cons-lightly, perhaps even go ahead and disable GC runs except at inter-level breaks...

IMO CLOS is a very nice object system for game code in an object-oriented style due to multiple dispatch (see wikipedia example):

http://en.wikipedia.org/wiki/Multiple_dispatch#Common_Lisp

http://lispbuilder.sourceforge.net/lispbuilder-sdl.html

http://common-lisp.net/project/cl-opengl/

When I last looked a while back (it might be neater now), the secret to getting cl-opengl and lispbuilder-sdl to play nice together was the following incantation, enabling use of opengl 2 shaders and stuff:

   ; N.B. don't use any ext. functions which go through GetProcAddress
   ; until AFTER an opengl sdl surface exists, presumably there's late binding going on...
   (setf cl-opengl-bindings:*gl-get-proc-address* #'sdl-cffi::sdl-gl-get-proc-address)

http://en.wikipedia.org/wiki/Gleeking

... or just use http://clive.sourceforge.net/ from the command line.

Indeed, I basically just have a desktop background picture so so there's something pretty slightly showing through translucent windows.

I used to just turn all icons off on the desktop, but recently I've started to use XFCE's desktop-icons-represent-running-applications mode - to switch between applications, I can hit the "show desktop" and select a different app. So my "desktop" is pretty much just a very spacious and pretty hiding task bar. Since I seldom have more than 10 or so GUI things running at once, the desktop is still mostly empty of icons so doesn't look like crap when it shows through.