Nathan Keynes has posted an update regarding Mac OS X support on his Linux-based Dreamcast emulator, lxdream.

The good news is that I now have regular access to a mac again, and it’s actually
fairly up-to-date (ie it’s running 10.5). So as a result, I have to say I’m stunned
that other people have managed to get as far as they did - as far as I can see,
Apple seems to have broken GLX pretty thoroughly[0].

So I’ve done 3 things:

-- Fixed the crashes at least, with glx, and generally fixed up the configure script
for 10.5. I’ve probably broken it for 10.4 though. Which raises the question - is
anyone actually trying to use lxdream on 10.4?
-- Added support for the native GTK port w/ NSGL. This actually works fairly
nicely. Unfortunately the only binary I can find for GTK/Quartz is provided by
macports, and the font support is broken at the moment (ie completely missing).
If anyone actually manages to build it from source… do let me know 
-- Started implementing a (fairly minimal) native cocoa UI. Well I was always going
to do this eventually, I just hadn’t been planning to do it _now_. 

In unrelated news, pulseaudio support is now in, along with spanish and italian
translations (thanks to segnini75 and ghost22)

[0] So far I’ve noticed: It’s restricted to 16-bit depth buffers, has various other
regressions from 10.4, creating a context with fbconfig crashes the app,
glSecondaryColorPointerEXT fails if given a size = 4 (and lead to a crash),
not to mention the libGL link cycle issue…

Source: lxdream.org