[R-SIG-Mac] build tools/x11 on leopard

[Kasper Daniel Hansen]

I am wondering what compiler I need to use under Leopard when I  
install packages from source using the experimental build of R-2.6- 
branch for x64 (from Simon's site), when I am running leopard. To my  
mind there are two options
1) The standard Xcode 3.0 gcc compiler
2) The preview of gcc 4.2 from the developers site, I think it has  
build number 5531
I think I need to go for option 2, comments?

Also (I am new to leopard) what should I do about X11. There seems to  
be two options.
1) Downgrade the Tigers X11
2) Install the Xquartz package from
http://trac.macosforge.org/projects/xquartz/wiki/X112.1.3

Again, I guess I should go for 2). But what is people's experience

Thanks
Kasper