What is Open Source Software (OSS) and what is the idea behind it? What are examples for popular Open Source Software, what are the Advantages about using OSS, what are the disadvantages.

1. Open Source Software
Agenda
1. What means Open Source (OS) and what is the idea behind it?
2. Examples for popular Open Source Software
3. Advantages about using OSS
4. Disadvantages about using OSS
5. Different Open Source licenses (GPL, LGPL, BSD License)
6. Thinking it further: Open Content

2. 1. What means Open Source and what is the idea behind it?
The most general meaning of the term Open Source is, that as a
user of a product you will get the all the source code and all the
documentation included with the product, so you can read it and
understand, how the product works.
The term „Open Source Software“ was created in 1998 as a new
label for Free Software. The idea behind is: Software or algorithms
in general are knowledge and knowledge should be free for everyone.
Free Software can be used, copied, studied, modified and
redistributed by everyone. It is different to „Freeware“, which is
free of charge but does not allow modification and redistribution.

3. 2. Examples for popular Open Source Software
Open Source Software became popular through
the spreading of the Linux operating system
which was developed and released in 1991 by
Finish programmer Linus Torvalds.
Other well known Open Source Software:
– Firefox or Mozilla webbrowser
– Open Office office suite
– grafical sofware like The GIMP
– server software like Apache or PHP
– database systems like MySQL or PostgreSQL

4. 3. Advantages about using Open Source Software:
– is free of charge
– has improved code quality
– spyware or backdoors are impossible
– is effective against software monopols
– open standards improve software interoperability
– suitable for educational use
– user is independent from software manufacturers
– programmer teams can manage bigger software-projects

5. 4. Disadvantages about using Open Source Software
– no or less personal support
– nobody is really responsible (by contract)
– for programmers it's difficult to earn money
– for programmers its hard to defend their product
– more security problems
– Total Cost of Ownership (TCO) is higher
Some of these are arguments must be seen critically because they
are from software manufacturers, that stand against OSS.

6. 5. The different Open Source licenses
– GNU General Public License (GPL)
– most popular (Linux)
– very restrictive
– not suited for commercial projects
– GNU Lesser General Public License (LGPL)
– less restrictive than GPL
– allows integration into proprietary software
– Other Open Source Licences
– Berkeley Software Distribution License (BSD)
– PHP License
– Apache License

7. 6. Open Content: The next step
By default every creative work like
a text, an image or foto is protected by
copyright laws and mostly using and redistribution is prohibited.
If you want to share your work with others and allow the use or
redistribution under certain conditions, you can make your work
available under an Open Content License.
The most popular Open Conent Licenses are:
– GNU Free Documentation License
used for example by Wikipedia.org
– Creative Commons License creativecommons.org
used by a lot of Weblogs