> It's interesting that you can think of a loop as of a 
> recursive function call that doesn't have to remember where 
> it came from because it doesn't have to go back.
> 

Oliver Becker reminded me recently of his loop compiler (preprocessor) which
allows you to write such constructs as loops rather than as recursive
template calls:

http://www2.informatik.hu-berlin.de/~obecker/XSLT/#loop-compiler

Michael Kay
http://www.saxonica.com/