[texhax] Change Tracking in LaTeX

[Charla Mustard-Foote]

Hello,

I'm new to this group (and to LaTeX) and I'm looking for a way to mark 
changes in the files created by
LaTex.  In other words, when I provide updated pdf files for my users, I 
want to be able to track changes there.

I'm using Linux and I'm about to tackle LyX but any other solutions will 
be most welcome!  Reply to me and I'll pass on information if anyone 
else wants it. 

tia

c