clarification on free/libre vs. OSS; closes OpenScienceMOOC#85

Author: fkohrt

content_development/MAIN.md

@@ -144,13 +144,23 @@ Check, check, check, done! Simples.
 
 ## The Open Source community and its governance <a name="OS_Community"></a>
 
-There are two main camps within the free software community: The **free software movement**, and the **OSS movement**. Both have differing ideologies based on user liberties and the practical applications of software. Often, the term 'FLOSS' is used to reconcile these two political camps, and means 'Free/Libre and Open Source Software'; Libre being French and Spanish for 'free' in the context of freedom.
+There are two main camps within the free/libre and open source software (FLOSS) community: The **free software movement**, and the **open source software movement** (OSS). Both have differing ideologies based on user liberties and the practical applications of software. The term 'FLOSS' is used as a overaching neutral term to refer to both; libre being French and Spanish for 'free' in the context of freedom.
 
-The core principle of re-use is what separates OSS from 'Free Software'. Free and Open Source Software (FOSS) is an inclusive term to describe software that can be classified as both free and Open Source. A good example of FOSS is the [Ubuntu Linux](https://www.ubuntu.com/) operation system.
+In a similar way that people active in the open science movement are heterogeneous in their assumptions and aims, different opinions exist in the FLOSS community as well. Recalling module 1, two of the schools of thought in open science were the _Pragmatic school_ and the _Democratic school_. While the former is driven by the assumption that research could be more efficient if scientists worked together, the latter wants to set straight an unequal distribution of knowledge. They probably both end up sharing their research, but each with different intentions.
 
-The big difference between free software and OSS is that the former must distribute updated versions under the same license as the original, whereas newer versions of OSS can be distributed under different licenses. FOSS combines the best of both worlds.
+This is roughly comparable to the OSS and the free software movement: The latter evolved around 1983 to protect what they call the four essential freedoms of a program's user. These include the freedom to run, copy, distribute, study, change and improve a program. Software that respects these freedoms with an appropriate license is considered 'free'. The four freedoms are seen as vital for a society as a whole in the sense that they only enable sharing, cooperation and ultimately freedom in general. In this sense the free software movement is a social movement that creates an ethical imperative.
 
-These definitions have now become widely adopted, both by international governments, as well as some large organisations such as the [Mozilla Foundation](https://www.mozilla.org/en-US/foundation/) and the [Wikimedia Foundation](https://wikimediafoundation.org/wiki/Home). Major organisations in the FLOSS space include the UK's [Software Sustainability Institute](https://www.software.ac.uk/), who produce valuable resources such as their recent [Software Deposit Guidance for Researchers](https://softwaresaved.github.io/software-deposit-guidance/).
+The open source software movement, which splintered off in 1998, focuses on the practical advantages and does not campaign for principles. It is concerned with developing high-quality software, for which everyone's ability to obtain, modify and contribute back the source code is considered highly beneficial.
+
+Among multiple conclusions they arrive at, access to a program's source code is a shared one. Software thus may be considered _free_, _open source_, or both, according to agreed-on definitions by the Free Software Foundation ([FSF](https://www.gnu.org/philosophy/free-sw.html)) and the Open Source Initiative ([OSI](https://opensource.org/osd)). The FSF argues that free software is a subset of OSS, with only a [fraction](https://www.gnu.org/philosophy/free-open-overlap.html) being open source but nonfree.
+
+Thus, highlighting a particular license status of software in use—open source or free—is mostly about different philosophies, not about software not having the other status as well. Each movement has its share of problems explaining their term: _free_ means more than being gratis and _open source_ means more than having access to the source code. It should be mentioned as well that the exact differences between free and open source are probably unknown to many who probably stick to the term encountered first or more often without further differentiation. The FSF provides a great deal of resources for further reading on the topic of software freedom, if interested start e. g. [here](https://www.gnu.org/philosophy/open-source-misses-the-point.html).
+
+Both movements had and still have a lasting impact on how software is developed and used. This is entirely evident in the domain of software professionals, but also partially evident for end-users: many operating systems are based on _GNU/Linux_, people use _Mozilla Firefox_ as their web browser, _LibreOffice_ as their office suite and the _VLC media player_ as their program for watching videos.
+
+Besides a software license being free or open source, it can also contain a _copyleft_ clause. This is about the question wether modified versions of the original program should be published under the same license as well. For someone who believes in the user's freedom, is it better to aim for most permissive licensing (such as releasing in the public domain) and thus allowing others to limit the users of their derived versions again? Or better make the own work more restrictive in the first place (choose a copyleft license), contrary to the higher goal of freedom, but more resistant in the long run? Quite imaginable, there are different opinions about this.
+
+The aforementioned definitions have now become widely adopted, both by international governments, as well as some large organisations such as the [Mozilla Foundation](https://www.mozilla.org/en-US/foundation/) and the [Wikimedia Foundation](https://wikimediafoundation.org/wiki/Home). Major organisations in the FLOSS space include the UK's [Software Sustainability Institute](https://www.software.ac.uk/), who produce valuable resources such as their recent [Software Deposit Guidance for Researchers](https://softwaresaved.github.io/software-deposit-guidance/).
 
 ### For individual projects