[XeTeX] What is synctex?

[Bruno Voisin]

Having built xetex from source on May 5 on the Mac

> theo9mc182:~ bvoisin$ xetex --version
> XeTeX 3.1415926-2.2-0.998.1 (Web2C 7.5.6)
> kpathsea version 3.5.6dev
> Copyright 2008 SIL International.
> Kpathsea is copyright 2008 Karl Berry and Olaf Weber.
> There is NO warranty.  Redistribution of this software is
> covered by the terms of both the XeTeX copyright and
> the Lesser GNU General Public License.
> For more information about these matters, see the file
> named COPYING and the XeTeX source.
> Primary author of XeTeX: Jonathan Kew.
> Kpathsea written by Karl Berry, Olaf Weber, and others.
>
> Compiled with ICU version 3.8.1 [with modifications for XeTeX]
> Compiled with zlib version 1.2.3; using 1.2.3
> Compiled with FreeType2 version 2.3.5; using 2.3.5
> Using Mac OS X Carbon, Cocoa & QuickTime frameworks

I just noticed that when using xelatex to typeset a .tex input file, a  
new file .synctex.gz is created in addition to the usual .log and .aux  
files.

Looking at the xetex source repository, one can indeed find a  
directory http://scripts.sil.org/svn-view/xetex/TRUNK/texk/web2c/synctex/ 
  and there a man page containing

> The Synchronization TeXnology is a new feature of recent TeX  
> engines. It allows to synchronize between input and output, which  
> means to navigate from the source document to the typeset material  
> and vice versa.
and later

> The Synchronize TeXnology is essentially due to Jerome Laurens, with  
> useful suggestions by some well known actors of the TeX world.


However, the man page also says

> Run `synctex help' to access the built-in tool documentation.
which doesn't seem to work

> theo9mc182:~ bvoisin$ synctex help
> -bash: synctex: command not found

Neither does "man synctex"

> theo9mc182:~ bvoisin$ man synctex
> Cannot open the message catalog "man" for locale "fr_FR.UTF-8"
> (NLSPATH="<none>")
>
> No manual entry for synctex

Is this all normal? Where can we find information on synctex? And how  
to disactivate it if required?

Bruno Voisin