Netpbm consists of code contributed by many authors.  In most of the
source code files, there is a copyright notice and license, telling
you what you may or may not do with the code.  All authors have granted
you the right to use and distribute their code without having to pay
them, as long as you meet some simple requirements.

Most of the components require you to include a copy of their
copyright notices and warranty disclaimers in any copies or
derivations you distribute.

Another restriction that some of the software has is that in order to
have permission to copy it (which includes writing anything derived
from it), you must distribute source code for your copy or derivation
and propagate the same restriction to people who would copy your
derivation.  In other words, the price the author wants for the use of
his proprietary work is your contribution to the free software cause.

One component prohibits you from selling it or using it in a
commercial way: hpcdtoppm.

Some components are contributed to the public domain.  

The copyrights on individual components of this package are detailed 
at appropriate places within the package.  A slightly out of date
summary of all the copyrights is in the file 'doc/copyright_summary'
in the Netpbm source tree.

Each component is a package of code and documentation; e.g. the 'pamcomp'
program and the pamcomp user manual go together and are licensed to the public
as a package.  The Netpbm manual is just a hyperlinked collection of such
component manuals.  Parts of the manual that are not tied to a particular
component of code and do not carry a copyright notice are in the public
domain.

As with most public open source software, no one really knows for sure
where the code came from.  It is possible that a contributor copied it
without license to do so.  That might mean any user of the code owes
someone royalties.  The Netpbm maintainer in particular has received
no warranties regarding any of the code in the package.  So consider
all the above to be modified by "to the best of the Netpbm
maintainer's knowledge."


Netpbm may practice valid patents, which would mean that you owe someone
royalties if you use the code.  This is a minuscule risk, though.
What is known about patents related to Netpbm is in the file
'doc/patent_summary' in the Netpbm source tree.