NX Client for MacOS/X was not able to find the Apple X11 Server

Although XQuartz is already installed, NoMachine NX Client (v3.5.0-7) on OS X 10.6 will complain about not being able to find Apple X11 in /Applications or /Applications/Utilities.

You can download and install X11 for OS X 10.6 from here (just not sure if it will install without first uninstalling XQuartz because XQuartz may be newer).

Or, simpler, create a symlink /Applications/Utilities/X11.app to point to /Applications/Utilities/XQuartz.app:
$ sudo ln -s /Applications/Utilities/XQuartz.app /Applications/Utilities/X11.app

OS X top command: sort by column

 After starting top, sort by column names by typing:

o<key>         Set primary sort key to : [+-]{command|cpu|pid
               |prt|reg|rprvt|rshrd|rsize|th|time|uid|username|vprvt
               |vsize}
O<skey>        Set secondary sort key to 

Field descriptions
command: command name
cpu: CPU usage
prt: number of Mach ports
reg: number of memory regions
rpvrt: resident (physical) private address space
rshrd: resident (physical) shared memory space
rsize: resident (physical) memory size
th: number of threads
time: execution time
uid: user ID
vprvt: private address space size
vsize: total virtual memory size