As of 1.7-10, the following changes have been made to the Debian version of
xless:

* We no longer use the IMakefile based Makefile, mostly just because it's
  really complex and I don't want to deal with it
* We no longer use the included regexp library, but instead rely on the 
  regexp functions built into glibc. This makes it easier to maintain.
* The only search type that is recognized now is regular expression search.
  The ExactMatch and CaseInsesitiveMatch in the original xless is not
  currently supported. If any of you really wants this back, please email
  me.
  
Randolph Chung <tausq@debian.org> Apr 11 1999