Software Engineering for Students A Programming Approach

324 Chapter 25 ■ Open source software development
a totally embracing ethic, increasing access to the practice of software development and
also the resultant products.
The philosophy of the FSF is that individual freedom should never be compromised
and that all individual action should also benefit the wider community. Therefore,
whilst individual programmers are encouraged and admired, they are also expected to
feed their findings and their skills back into the community of programmers to which
they ultimately belong. This is done through the sharing of code and the distribution
of good programming practice.
The FSF is absolutely resolute in not allowing any proprietary software to be incorporated
into their software and were integral in the creation of the GPL. All their products
are covered under the GPL, and they are largely unaffiliated with larger software
development companies.
The Open Source Movement is spearheaded by Eric S. Raymond. Their emphasis is
on the benefits of open source as a development approach, rather than the moral benefits
that can be brought by using this approach. They stress that open source can produce
higher-quality software than proprietary software.
The OSM are more willing to collaborate with larger software companies, sometimes
including developers of proprietary products. They wish to appeal to the business sector
because this enables greater distribution of their product. However, unlike the FSF,
greater use of their products is motivated primarily because of the quality, rather than
because of the freeness of the software. Forming contracts with larger companies is one
way of exposing OSM products to a larger potential market. However, it also means
that the product must compete with other commercial package products.
25.4 ● Techniques of open source development
Despite the schism within open source in terms of ethics and philosophy, the development
practices principally remain the same between the two.
Within the open source development community, there is often no formal mechanism
for gathering initial user requirements. The process often consists of a software requirement
that is instigated by a sole developer, with requests for collaboration, targeting the
hacker community. The Internet facilitates communication between developers and also
the distribution of source code, via the Web, File Transfer Sites and e-mail.
The head developer specifies most requirements. Additional user requirements are
either implemented by individual developers themselves via personal modification of
the source code, or through a communal process known as “code forking”. Code forking
occurs when the developer base has alternative requirements or conflicting ideas on
how to implement a requirement. The code is seen to “fork” because it is split and each
copy of the code is developed in parallel. After this split occurs, the code is irreconcilable
and therefore two different products exist, both growing from the same base code.
Each fork competes for developer attention, so that the most popular or the most reliable
version survives.
The code writing on an open source project is sustained through voluntary contributions.
Developers are motivated by the enjoyment of programming, the belief in the