No discrimination against persons or groups -- The license must allow all people to be
equally eligible to use the source code.
No discrimination against fields of endeavor -- The license can't restrict a project from
using the source code because it is commercial or because it is associated with a field of
endeavor that the software provider doesn't like.
Distribution of license -- No additional license should be needed to use and redistrib-
ute the software.
License must not be specific to a product -- The license can't restrict the source code
to a particular software distribution.
License must not restrict other software -- The license can't prevent someone from
including the open source software on the same medium as nonopen source software.
License must be technology-neutral -- The license can't restrict methods in which the
source code can be redistributed.
Open source licenses used by software development projects must meet these criteria to be
accepted as open source software by OSI. More than 40 different licenses are accepted by OSI to be
used to label software as "OSI Certified Open Source Software." In addition to the GPL, other pop-
ular OSI-approved licenses include:
LGPL -- The GNU Lesser General Public License (LGPL) is a license that is often used for
distributing libraries that other application programs depend upon.
BSD -- The Berkeley Software Distribution License allows redistribution of source code,
with the requirement that the source code keep the BSD copyright notice and not use the
names of contributors to endorse or promote derived software without written permission.
MIT -- The MIT license is like the BSD license, except that it doesn't include the endorse-
ment and promotion requirement.
Mozilla -- The Mozilla license covers use and redistribution of source code associated
with the Mozilla Web browser and related software. It is a much longer license than the
others just mentioned because it contains more definitions of how contributors and those
reusing the source code should behave. This includes submitting a file of changes when
submitting modifications and that those making their own additions to the code for redis-
tribution should be aware of patent issues or other restrictions associated with their code.
The end result of open source code is software that has more flexibility to grow and fewer bound-
aries in how it can be used. Many believe that the fact that many people look over the source code
for a project will result in higher quality software for everyone. As open source advocate Eric S.
Raymond says in an often-quoted line, "Many eyes make all bugs shallow."
Vibrant Communities
Communities of professionals and enthusiasts have grown around Linux and its related open
source projects. Many have shown themselves willing to devote their time, knowledge, and skills
18
Linux First Steps
Part I
