JEREMYHU  Yes, I would very much like to know how 2.4.1_alpha3 got listed on this site. It wasn't updated by me (the developer). I was as shocked as anybody to see that version being advertised here. The only place I announce alpha and beta versions is the development list (xquartz-dev). Release candidates are announced on x11-users. Final versions are mentioned on the website and updated here.

If you are a casual user, I advise you to stick with 2.4.0 on Leopard or the shipping version of 2.3.4 on SnowLeopard. If you got suckered into 2.4.1_alpha3 by this site, follow these steps to get rid of it:

1) Open Terminal.app

2) Run this:

sudo rm -rf /opt/X11 /Applications/Utilities/XQuartz.app /Library/Launch*/org.macosforge.xquartz.*

3) Logout and Login  
(Version 2.4.1_alpha3)

JEREMYHU  Crashy and buggy. Unstable to the point of unusability.  
(Version 1.1v53)

JEREMYHU  This software is pure garbage. Do NOT get suckered into paying $25 for it. It crashes within 15 seconds of use. I've seen 4 different crashes and emailed the developer with no response. This is garbage.  
(Version 1.1v53)

JEREMYHU  We've had no reports of this problem from anyone else. Please file a bug report at http://xquartz.macosforge.org and we'll help you, but there's really no way why this should cause your computer to not boot since it doesn't do anything to the boot process.  
(Version 2.2.1)