[Rd] literate programming

[Terry Therneau]

"ESS supported noweb before Sweave existed."
   
   That is the bit I didn't know.  What I was rather looking for was a noweb 
mode that knows about S formatting, and here it was available all along.  I've 
used a version of ESS for a loooong time - probably should re-read the 
documentation one of these days to catch up on all the new features!
   
   "and the latex
syntax was added lateron because some people write whole packages using
noweb and would have had a syntax conflict in their vignettes"

  I'm not quite sure what this means.  
  
  	Thanks much,
  	
  		Terry Therneau