So I took a look and this the weirdest modification of the BSD license because it restricts redistribution. That makes it not open source or Libre right? I wonder what happens if I just look and copy the css style sheet and themes of their site, I would have to put "powered by Attendize" somewhere?
It also does what Mozilla does (or used to do?) which is restrict the use of a trademark.
All Rights Reserved
ATTRIBUTION ASSURANCE LICENSE (adapted from the original BSD license)
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the conditions below are met.
These conditions require a modest attribution to Attendize.com. The hope
is that its promotional value may help justify the thousands of dollars in
otherwise billable time invested in writing this and other freely available,
open-source software.
1. Redistributions of source code, in whole or part and with or without
modification requires the express permission of the author and must prominently
display "Powered by Attendize" or the Attendize logo in verifiable form
with hyperlink to said site.
2. Neither the name nor any trademark of the Author may be used to
endorse or promote products derived from this software without specific
prior written permission.
3. Users are entirely responsible, to the exclusion of the Author and
any other persons, for compliance with (1) regulations set by owners or
administrators of employed equipment, (2) licensing terms of any other
software, and (3) local regulations regarding use, including those
regarding import, export, and use of encryption software.
THIS FREE SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
EVENT SHALL THE AUTHOR OR ANY CONTRIBUTOR BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
EFFECTS OF UNAUTHORIZED OR MALICIOUS NETWORK ACCESS;
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.