Open source

Definition

• Open source is software that can be modified (because it is distributed along with its source code).

• Usually (at least at the time of this writing), open source also means free.

Typology of open source models

There are several criteria which can be combined:

1. Cost:
   • Free
   • Free for certain communities
   • Commercial
2. Open source:
   • Source code is (not) available
3. Copyright:
   • "Free as beer" (you can do what you want),
   • Restricted to insure "continuation", e.g. GPL style that will not allow you to change copyright on derivative works
   • Restricted

Well known copyright schemas

There are many "open source" licenses and variants ! Please follow the links in Wikipedia:Open-source software for details...

GNU General Public License] (GPL)

GPL grants the recipients the following rights (or freedoms):

• to run the program, for any purpose.
• to study how the program works, and modify it. (Access to the source code is a precondition for this)
• to redistribute copies.
• to improve the program, and release the improvements to the public. (Access to the source code is a precondition for this)

In addition he GPL seeks to ensure that the above freedoms are preserved in copies and in derivative works. It does this using a legal mechanism known as copyleft.

(see Wikipedia: Free software for finer points)

BSD License

This license has few restrictions on it compared to other licenses such as the GNU GPL or even the default restrictions provided by copyright, putting it relatively closer to the public domain. (Indeed, the BSD License has been referred to as copycenter, for comparison to both standard copyright and the GPL's copyleft: "Take it down to the copy center and make as many copies as you want". (see Wikipedia: BSD license for details).

Apache license

• The Apache License (versions 1.0, 1.1, and 2.0) require preservation of the copyright notice and disclaimer, but it is not a copyleft license - it allows use and distribution of the source code in both open source and closed source software.
• This license is used by all "Apache" products (e.g. the Apache webserver), but other people adopted it as well.

(see Wikipedia: Apache License for details).

Creative commons (various variants)

under construction

Open source in education

<< The advantage of Open Source Software (OSS) which one hears mentioned most frequently is that it is free and can be adapted and extended to meet ones own needs. More important, in my opinion, is the advantage educational institutes can obtain by applying OSS: to shape e-learning according to a clear vision of the educational methods one plans to apply >> (de Vries, 2004).

De Vries (2004) distinguishes four stages or phases of OSS adoption

1. Promote the use of OS, do not develop yourself under OS
2. Develop with OS in specific projects
3. Use and development takes place primarily with OS
4. Use and development takes place primarily with OS with active participation in community

The latest model is course the most interesting to us.

References

• Wikipedia articles: Wikipedia:Open-source software, Wikipedia: Open source, Wikipedia: GNU General Public license

• Fred de Vries (2004): Why should institutions apply Open Source Virtual Learning Environments ? [1] (text) [2] (pdf)