This is the file /usr/local/teTeX/share/texmf.gwtex/README.texmf.gwtex. A
symbolic link to this file is maintained in /usr/local/teTeX

The following setup has been created. There are four directories for texmf
trees to be kept. The support files installed by a make of TeX Programs is in
/usr/local/teTeX/share/texmf. The official tree is at
/usr/local/teTeX/share/texmf.tetex.  teTeX can handle multiple trees. A file
found in one overrides one found in the other. The order of search is set in
environment variables which are set in a file called texmf.cnf. Luckily, there
is also the possibility to have a local texmf.cnf as
/usr/local/teTeX/texmf.cnf, this possibility is compiled into the TeX
programs.

So here is what I have chosen to do:
0. Make sure the texmf trees for programs and the foundation are separate so
that they can be updated separately.
1. Keep the original texmf tree as default as possible, so that you may
upgrade it from a new teTeX release without destroying local modifications.
2. Make a second tree where Mac OS X specific settings and personal additions
are stored (e.g. use of type1 fonts) as well as additional packages that are
not in teTeX
3. Have a third tree where local modifications are stored. This is normal for
a unix TeX setup (the texmf-local tree).

0. /usr/local/teTeX/share/texmf is the texmf tree with the program support
stuff like the pool files, this is maintained by the TeX community. This tree
corresponds to the TeX Programs i-packages.

1. /usr/local/teTeX/share/texmf.tetex is the default teTeX texmf tree, this is
maintained by Thomas Esser. This tree corresponds to the TeX Foundation
i-packages.

2. /usr/local/teTeX/share/texmf.gwtex is the Mac OS X tree, this is maintained
and distributed by me. This tree corresponds to the TeX Foundation i-packages.

3. /usr/local/teTeX/share/texmf.local is the local texmf tree, this is
maintained by the local TeX administrator. It is also the VARTEXMF tree that
is handled in a special way by texconfig, e.g. formats and changes are stored
here. A package like CM-Super installs here by default so it will survive a
reinstall/upgrade of either TeX Programs or TeX Foundation i-packages.

The above trees are only searched through the tex hash.

4. In this Mac OS X distribution, user trees in ~/Library/texmf are active
as well but they do not use a hash for lookup.

PLEASE read also the file README.howtexfindsfiles before asking me why files
are not found by TeX.
