Dear Thomas,

I found the folder /usr/local/Build/powerpc/TeXLive.2006. I  
remembered that I have tried to install TeX using the source before.

When I open terminal, .luatex in not implemented yet and "texexec -- 
make --all --pdftex" run  without any errors.

%%%%%%%%%%%%%%%%%
texexec --make --all --pdftex

TeXExec | using search method 'kpsewhich'
TeXExec | updating file database
mktexlsr: Updating /usr/local/gwTeX/texmf/ls-R...
mktexlsr: Updating /usr/local/gwTeX/texmf.gwtex/ls-R...
...
mktexlsr: Done.
TeXExec | using tex engine pdftex
TeXExec | using tex format path /Users/dalyoung/Library/texmf/web2c/ 
pdftex
TeXExec | generating tex format cont-en
This is pdfTeX, Version 3.141592-1.40.3 (Web2C 7.5.6) (INITEX)
(/usr/local/gwTeX/texmf.pkgs/web2c/natural.tcx)
...
%%%%%%%%%%%

As you see in the above output, it uses the searching method 'kpsewhich'
and '/usr/local/gwTeX/texmf.pkgs/web2c/natural.tcx'
But after running 'source ~/.luatex', it used the same searaching  
path but different path for format and engine paths as following even  
though I removed /usr/local/Build folder.
However, to run 'luatools --generate', I need to run .luatex.
Still, I have a problem in 'luatools --ini --compile...'.
%%%%%%%%%%%%%%%
  texexec --make --all --pdftex

TeXExec | using search method 'kpsewhich'
TeXExec | updating file database
...
TeXExec | using tex engine pdftex
TeXExec | using tex format path /usr/local/Build/powerpc/TeXLive.2006/ 
texmf/web2c/pdftex
TeXExec | generating tex format cont-en
...
TeXExec | tex engine path: /usr/local/Build/powerpc/TeXLive.2006/ 
texmf/web2c/pdftex
TeXExec | mps engine path: /usr/local/Build/powerpc/TeXLive.2006/ 
texmf/web2c
...
%%%%%%%%%%%%

So I think that .luatex change the setting for the ConTeXt.
I attached .luatex file which shows the TDS in my mac.
By the  way, what is 'whence'? It is a unknown cmd in my machine.
and how to remove '/usr/local/Build/...' from the engine path?

Thank you for your help.

Best regards,

Dalyoung