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Open Source ( Licensing )

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An open source license is a copyright license for computer software that makes the source code available under terms that allow for modification and redistribution without having to pay the original author. Such licenses may have additional restrictions such as a requirement to preserve the name of the authors and the copyright statement within the code. One popular (and sometimes considered normative) set of open source software licenses are those approved by the Open Source Initiative (OSI) [1] based on their Open Source Definition (OSD) [2].


Open Source Logo

HHIS I should have touhhgt of that!

Contents

[edit] Main Licenses in Open Source

[edit] FSF (Free Software Foundation )

[edit] The GNU General Public License : GPL

The GNU General Public License (GNU GPL or simply GPL) is a widely used free software licence, originally written by Richard Stallman for the GNU project. The GPL is the most popular and well-known example of the type of strong copyleft licence that requires derived works to be available under the same copyleft. Under this philosophy, the GPL is said to grant the recipients of a computer program the rights of the free software definition and uses copyleft to ensure the freedoms are preserved, even when the work is changed or added to.

[edit] Version 1 ( January 1989 )

GPLv1 said that any vendor distributing binaries must also make the human readable source code available under the same licensing terms.

GPLv1 said that modified versions, as a whole, had to be distributed under the terms in GPLv1. Therefore, software distributed under the terms of GPLv1 could be combined with software under more permissive terms, as this would not change the terms under which the whole could be distributed, but software distributed under GPLv1 could not be combined with software distributed under a more restrictive licence, as this would conflict with the requirement that the whole be distributable under the terms of GPLv1.

[edit] Version 2 ( June 1991 )

According to Richard Stallman, the major change in GPLv2 was the "Liberty or Death" clause, as he calls it. This section says that if someone has restrictions imposed that prevent him or her from distributing GPL-covered software in a way that respects other users freedom (for example, if a legal ruling states that he or she can only distribute the software in binary form), he or she cannot distribute it at all.

By 1990, it was becoming apparent that a less restrictive licence would be strategically useful for some software libraries; when version 2 of the GPL (GPLv2) was released in June 1991, therefore, a second licence - the Library General Public License (LGPL) was introduced at the same time and numbered with version 2 to show that both were complementary. The version numbers diverged in 1999 when version 2.1 of the LGPL was released, which renamed it the GNU Lesser General Public License to reflect its place in the GNU philosophy.

Version 2 complete description

I'm out of league here. Too much brain power on disaply!

[edit] LGPL

The GNU Lesser General Public License (formerly the GNU Library General Public License) or LGPL is a free software license [3] published by the Free Software Foundation [4]. It was designed as a compromise between the strong-copyleft [5] GNU General Public License GNU General Public License or GPL [6] and permissive licenses such as the BSD licenses [7] and the MIT License [8]. The GNU Lesser General Public License was written in 1991 (and updated in 1999, and again in 2007) by Richard Stallman [9], with legal advice from Eben Moglen [10].

The LGPL places copyleft restrictions on the program itself but does not apply these restrictions to other software that merely links with the program. There are, however, certain other restrictions on this software.

The LGPL is primarily used for software libraries, although it is also used by some stand-alone applications, most notably Mozilla [11] and OpenOffice.org [12]

The main difference between the GPL and the LGPL is that the latter can be linked to (in the case of a library, 'used by') a non-(L)GPLed program, which may be free software or proprietary software. This non-(L)GPLed program can then be distributed under any chosen terms if it is not a derivative work. If it is a derivative work, then the terms must allow "modification for the customer's own use and reverse engineering for debugging such modifications." Whether a work that uses an LGPL program is a derivative work or not is a legal issue. A standalone executable that dynamically links to a library is generally accepted as not being a derivative work. It would be considered a "work that uses the library".

Essentially, it must be possible for the software to be linked with a newer version of the LGPL-covered program. The most commonly used method for doing so is to use "a suitable shared library mechanism for linking". Alternatively, a statically linked library is allowed if either source code or linkable object files are provided.

One feature of the LGPL is that one can convert any LGPLed piece of software into a GPLed piece of software. This feature is useful for direct reuse of LGPLed code in GPLed libraries and applications, or if one wants to create a version of the code that software companies cannot use in proprietary software products.

[edit] BSD ( Berkeley Software Distribution )

The BSD License allows proprietary commercial use, and for the software released under the license to be incorporated into proprietary commercial products. Works based on the material may even be released under a proprietary license (but still must maintain the license requirements). Some notable examples of this are the use of BSD networking code in Microsoft products,and the use of numerous FreeBSD components in Mac OS X.

It is possible for something to be distributed with the BSD License and some other license to apply as well. This was in fact the case with very early versions of BSD itself, which included proprietary material from AT&T.

As originally distributed, the BSD license had an extra clause, requiring authors of all works deriving from a BSD-licensed work to include an acknowledgment of the original source. This is numbered as clause 3 in the original license text: 

    * 3. All advertising materials mentioning features or use of this software
    *    must display the following acknowledgement:
    *    This product includes software developed by the University of
    *    California, Berkeley and its contributors.

This clause has been objected to on the grounds that as people changed the license to reflect their name or organisation it led to escalating advertising requirements when programs were combined together in a software distribution—every occurrence of the license with a different name requires a separate acknowledgement— the Free Software Foundation has cited the requirement for 75 such acknowledgments when advertising a 1997 version of NetBSD. In addition, it presents a legal problem for those wishing to publish BSD-licensed software which relies upon separate programs using the more-restrictive GPL: the advertising clause is incompatible with the GPL, which does not allow the addition of restrictions beyond those it already imposes.

The advertising clause was removed from the official BSD license text on July 22, 1999 by William Hoskins, the director of the office of technology licensing for Berkeley.

The original license is now sometimes called "BSD-old" or "4-clause BSD", while the current revision of the BSD license is sometimes referred to by names including "BSD-new", "revised BSD", or "3-clause BSD".

Some derived BSD licenses:

[edit] References

Licenses that are popular and widely used or with strong communities

http://en.wikipedia.org/wiki/Open_source_license (Open Sources Licenses) [21]

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