PURPOSE

Krona is a flexible tool for exploring the relative proportions of
hierarchical data, such as metagenomic classifications, using a
radial, space-filling display. It is implemented using HTML5 and
JavaScript, allowing charts to be explored locally or served over the
Internet, requiring only a current version of any major web
browser. Krona charts can be created using an Excel template or from
common bioinformatic formats using the provided conversion scripts.


COPYRIGHT LICENSE

Copyright © 2011, Battelle National Biodefense Institute (BNBI);
all rights reserved. Authored by: Brian Ondov, Nicholas Bergman, and
Adam Phillippy

This Software was prepared for the Department of Homeland Security
(DHS) by the Battelle National Biodefense Institute, LLC (BNBI) as
part of contract HSHQDC-07-C-00020 to manage and operate the National
Biodefense Analysis and Countermeasures Center (NBACC), a Federally
Funded Research and Development Center.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

* Redistributions of source code must retain the above copyright
  notice, this list of conditions and the following disclaimer.

* Redistributions in binary form must reproduce the above copyright
  notice, this list of conditions and the following disclaimer in the
  documentation and/or other materials provided with the distribution.

* Neither the name of the Battelle National Biodefense Institute nor
  the names of its contributors may be used to endorse or promote
  products derived from this software without specific prior written
  permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"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 COPYRIGHT
HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, 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.


TRADEMARK LICENSE

KRONA™ is a trademark of the Department of Homeland Security, and use
of the trademark is subject to the following conditions:

* Distribution of the unchanged, official code/software using the
  KRONA™ mark is hereby permitted by the Department of Homeland
  Security, provided that the software is distributed without charge
  and modification.

* Distribution of altered source code/software using the KRONA™ mark
  is not permitted unless written permission has been granted by the
  Department of Homeland Security.


PATENTS

The Krona software is not eligible for patent because there have been
previous and open implementations of this visualization method since
the year 2000 (e.g. "Focus+context display and navigation techniques
for enhancing radial, space-filling hierarchy visualizations." Stasko,
J. and Zhang, E. InfoVis, 2000). Krona represents a reimplementation and
application of an existing method to the new domain of
metagenomics. BNBI, as the copyright holders, wish to release Krona
freely and openly as a service to the bioinformatics community.


POINT OF CONTACT

Todd Harrington
General Counsel
Battelle National Biodefense Institute
harringtont@nbacc.net

