/debug directory -- what is it?

[To Thine Own Self be True.]

Hello all, 

      What is the /debug directory for?  I've looked through the
manuals and can't find anything on it.  Seems its taking up a rather
large portion of our disk space, but I've never seem much of it used.

      Anyway I can reduce its space (or is this even desirable?) ?

Thanks
 Jason Ruiter
 ORNL, FED
 (615) 574 1308
 ruiterjr at fedc04.fed.ornl.gov