Doug Tidwell is one of IBM's XML advocates. You may have read some of his articles
such as
Transforming XML into HTML [requires free login]
on IBM's informative
developerWorks site, XML section.
The site has great articles, code samples, tools, etc.
Tidwell made a distinction between customization which is something that a site user
consciously does himself by making various choices, and personalization which
is something that site software does without any overt action by the user,
except perhaps enabling cookies (e.g., targeting Amazon and CD Now).
