
   Wasn't the shareware fee a "suggestion" by John?
   Is so then it's up to the individual to make the choice whether or not to
   honour it and part with money.  Personally if I was in his position I would
   do exactly the same thing, John has obviously put in lot of time and effort
   into xv and why shouldn't he receive some money for it.

It is interesting to look at the change(s) of mind that John has had.

The AUTHOR file for xgif (an early incarnation of xv) reads (in part) 
as follows...

  Do whatever you want with this program, though it *would* be nice if my name
  remained on it somewhere...  Other than that, it may be freely modified,
  distributed, and used to fill up disk space.

The README file for xv 1.00 (?) reads (in part) as follows...

  NOTE:  If you like the program and decide to use it, *please* send me a short
  email message to that effect.  Be sure to mention the full name of your
  organization.  When our sponsors ask us 'what have you been doing', it would
  be most handy to be able to come up with a nice long list of organizations
  that are using code developed in the GRASP Lab.  Brownie points, as
  it were.

The copyright notices as it appeared then was...

  /*
   * Copyright 1989, 1990 by the University of Pennsylvania
   *
   * Permission to use, copy, and distribute for non-commercial purposes,
   * is hereby granted without fee, providing that the above copyright
   * notice appear in all copies and that both the copyright notice and this
   * permission notice appear in supporting documentation.
   *
   * The software may be modified for your own purposes, but modified versions
   * may not be distributed.
   *
   * This software is provided "as is" without any express or implied warranty.
   */

The README file for xv 2.00 reads (in part) as follows...

  Also, if you find XV to be nifty, useful, generally 'cool', and of
  some value to you, your donation (not tax-deductable) would be greatly
  appreciated.  $10 (U.S.) is probably a fine amount to donate.
  Folks who donate $25 and up will receive a nice, bound copy of the XV Manual
  printed on a spiffo 600-dpi laser printer.  It'll look lovely mounted over
  your fireplace.

Which looks to me as a suggestion (see Julian's comment above).

The copyright notices as it appeared then was...

  * Copyright 1989, 1990, 1991, 1992 by John Bradley and
  *                       The University of Pennsylvania

The README for xv 3.00 reads (in part) as follows...

  XV is shareware for PERSONAL USE only.  You may use XV for your own
  amusement, and if you find it nifty, useful, generally cool, or of
  some value to you, your non-deductable donation would be greatly
  appreciated.  $25 is the suggested donation, though, of course,
  larger donations are quite welcome.  Folks who donate $25 or more
  can receive a printed, bound copy of the XV manual for no extra
  charge.  If you want one, just ask.  BE SURE TO SPECIFY THE VERSION
  OF XV THAT YOU ARE USING!

  Commercial, government, and institutional users MUST register their
  copies of XV, for the exceedingly REASONABLE price of just $25 per
  workstation/X terminal.  Site licenses are available for those who
  wish to run XV on a large number of machines.  Contact the author
  for more details.

The second paragraph to me says that universities MUST register and
pay (a potentially) large sum of money.

The copyright notices now read...

  * Copyright 1989, 1990, 1991, 1992, 1993 by John Bradley

Was this developed on upenn's time/equipment?  What do they, and the
GRASP lab mentioned above, have to say about all this?