View source for Open-source software development

{{Short description|Freely accessible creation and refinement of computer programs}}
'''Open-source software development (OSSD)''' is the process by which [[open-source software]], or similar software whose [[Source Code Management|source code]] is publicly available, is developed by an '''open-source software project'''. These are software products available with its source code under an [[open-source license]] to study, change, and improve its design. Examples of some popular open-source software products are [[Mozilla Firefox]], [[Chromium (web browser)|Google Chromium]], [[Android (operating system)|Android]], [[LibreOffice]] and the [[VLC media player]].

== History ==
In 1997, [[Eric S. Raymond]] wrote ''[[The Cathedral and the Bazaar]]''.<ref name=Raymond>Raymond, E.S. (1999). ''The Cathedral & the Bazaar''. O'Reilly Retrieved from http://www.catb.org/~esr/writings/cathedral-bazaar/.</ref> In this book, Raymond makes the distinction between two kinds of [[software development]]. The first is the conventional [[closed-source]] development. This kind of development method is, according to Raymond, like the building of a cathedral; central planning, tight organization and one process from start to finish. The second is the progressive open-source development, which is more like "a great babbling bazaar of differing agendas and approaches out of which a coherent and stable system could seemingly emerge only by a succession of miracles." The latter analogy points to the discussion involved in an open-source development process.

Differences between the two styles of development, according to Bar and Fogel, are in general the handling (and creation) of [[Bug report|bug reports]] and [[feature requests]], and the constraints under which the programmers are working.<ref name=Barfogel>Bar, M. & Fogel, K. (2003). ''Open Source Development with CVS'', 3rd Edition. Paraglyph Press. ({{ISBN|1-932111-81-6}})</ref> In closed-source software development, the programmers are often spending a lot of time dealing with and creating bug reports, as well as handling feature requests. This time is spent on creating and prioritizing further development plans. This leads to part of the development team spending a lot of time on these issues, and not on the actual development. Also, in closed-source projects, the development teams must often work under management-related constraints (such as deadlines, budgets, etc.) that interfere with technical issues of the software. In open-source software development, these issues are solved by integrating the users of the software in the development process, or even letting these users build the system themselves.{{Citation needed|date=November 2014}}

== Model ==
{{distinguish|Open-source model}}
[[Image:Process-data diagram of open source software development.png|thumb|250px|Process-Data Model for open-source software development]]

Open-source software development can be divided into several phases. The phases specified here are derived from ''Sharma et al''.<ref name=Sharma>Sharma, S., Sugumaran, V. & Rajagopalan, B. (2002). ''A framework for creating hybrid-open source software communities''. Information Systems Journal 12 (1), 7 – 25.</ref> A diagram displaying the process-data structure of open-source software development is shown on the right. In this picture, the phases of open-source software development are displayed, along with the corresponding data elements. This diagram is made using the [[meta-modeling]] and [[meta-process modeling]] techniques.

=== Starting an open-source project ===

There are several ways in which work on an open-source project can start:

# An individual who senses the need for a project announces the intent to develop a project in public.
# A developer working on a limited but working codebase, releases it to the public as the first version of an open-source program.
# The source code of a mature project is released to the public.
# A well-established open-source project can be [[Fork (software development)|forked]] by an interested outside party.

Eric Raymond observed in his essay ''The Cathedral and the Bazaar'' that announcing the intent for a project is usually inferior to releasing a working project to the public.

It's a common mistake to start a project when contributing to an existing similar project would be more effective ([[Not Invented Here#In the free software community|NIH syndrome]]){{Citation needed|date=October 2019}}. To start a successful project it is very important to investigate what's already there. The process starts with a choice between the adopting of an existing project, or the starting of a new project. If a new project is started, the process goes to the Initiation phase. If an existing project is adopted, the process goes directly to the Execution phase.{{Original research inline|date=October 2019}}

== Types of open-source projects ==
{{see also|List of free and open-source software packages}}

Several types of open-source projects exist. First, there is the garden variety of software programs and libraries, which consist of standalone pieces of code. Some might even be dependent on other open-source projects. These projects serve a specified purpose and fill a definite need. Examples of this type of project include the [[Linux kernel]], the Firefox web browser and the LibreOffice office suite of tools.

Distributions are another type of open-source project. Distributions are collections of software that are published from the same source with a common purpose. The most prominent example of a "distribution" is an operating system. There are many [[Linux distribution|Linux distributions]] (such as [[Debian]], [[Fedora Linux|Fedora Core]], [[Mandriva]], [[Slackware]], [[Ubuntu]] etc.) which ship the Linux kernel along with many user-land components. There are other distributions, like [https://web.archive.org/web/20160331201814/http://www.activestate.com/activeperl ActivePerl], the [[Perl|Perl programming language]] for various operating systems, and [[Cygwin]] distributions of open-source programs for [[Microsoft Windows]].

Other open-source projects, like the [[Berkeley Software Distribution|BSD]] derivatives, maintain the source code of an entire operating system, the kernel and all of its core components, in one [[revision control]] system; developing the entire system together as a single team. These operating system development projects closely integrate their tools, more so than in the other distribution-based systems.

Finally, there is the book or standalone document project. These items usually do not ship as part of an open-source software package. [[Linux Documentation Project]] hosts many such projects that document various aspects of the Linux operating system. There are many other examples of this type of open-source project.

== Methods ==

It is hard to run an open-source project following a more traditional software development method like the [[waterfall model]], because in these traditional methods it is not allowed to go back to a previous phase. In open-source software development, requirements are rarely gathered before the start of the project; instead they are based on early releases of the software product, as Robbins describes.<ref name=Robbins>Robbins, J. E. (2003). ''Adopting Open Source Software Engineering (OSSE) Practices by Adopting OSSE Tools''. Making Sense of the Bazaar: Perspectives on Open Source and Free Software, Fall 2003.</ref> Besides requirements, often volunteer staff is attracted to help develop the software product based on the early releases of the software. This [[network effect|networking effect]] is essential according to Abrahamsson et al.: “if the introduced prototype gathers enough attention, it will gradually start to attract more and more developers”. However, Abrahamsson et al. also point out that the community is very harsh, much like the business world of closed-source software: “if you find the customers you survive, but without customers you die”.<ref name=Abrahamsson>Abrahamsson, P, Salo, O. & Warsta, J. (2002). ''Agile software development methods: Review and Analysis''. VTT Publications.</ref>

Fuggetta<ref name=Fuggetta>{{cite journal|first1=Alfonso|last1=Fuggetta|title=Open source software––an evaluation|journal=Journal of Systems and Software|date=2003|pages=77–90|volume=66|issue=1|doi=10.1016/S0164-1212(02)00065-1}}</ref> argues that “rapid prototyping, incremental and evolutionary development, spiral lifecycle, rapid application development, and, recently, extreme programming and the agile software process can be equally applied to proprietary and open source software”. He also pinpoints [[Extreme Programming]] as an extremely useful method for open source software development. More generally, all [[Agile programming]] methods are applicable to open-source software development, because of their iterative and incremental character. Other Agile methods are equally useful for both open and closed source software development: [[Internet-Speed Development]], for example is suitable for open-source software development because of the distributed development principle it adopts. Internet-Speed Development uses geographically distributed teams to ‘work around the clock’. This method, mostly adopted by large closed-source firms, (because they're the only ones which afford development centers in different time zones), works equally well in open source projects because a software developed by a large group of volunteers shall naturally tend to have developers spread across all time zones.

== Tools ==
{{unreferenced section|date=May 2013}}

=== Communication channels ===

Developers and users of an open-source project are not all necessarily working on the project in proximity. They require some electronic means of communications. [[Email]] is one of the most common forms of communication among open-source developers and users. Often, [[electronic mailing list]]s are used to make sure e-mail messages are delivered to all interested parties at once. This ensures that at least one of the members can reply to it. In order to communicate in real time, many projects use an [[instant messaging]] method such as [[Internet Relay Chat|IRC]]. Web forums have recently become a common way for users to get help with problems they encounter when using an open-source product. [[Wiki]]s have become common as a communication medium for developers and users.<ref name=":0">{{cite magazine|url=https://www.wired.co.uk/magazine/archive/2014/03/web-at-25/tim-berners-lee|title=Tim Berners-Lee on the Web at 25: the past, present and future|magazine=Wired UK}}</ref>

=== Version control systems ===
{{Main article|Revision control}}

In OSS development the participants, who are mostly volunteers, are distributed amongst different geographic regions so there is need for tools to aid participants to collaborate in the development of source code.

During early 2000s, [[Concurrent Versions System]] (CVS) was a prominent example of a source code collaboration tool being used in OSS projects. CVS helps manage the files and codes of a project when several people are working on the project at the same time. CVS allows several people to work on the same file at the same time. This is done by moving the file into the users’ directories and then merging the files when the users are done. CVS also enables one to easily retrieve a previous version of a file. During mid 2000s, [[Apache Subversion|The Subversion revision control system]] (SVN) was created to replace CVS. It is quickly gaining ground as an OSS project version control system.<ref name=":0" />

Many open-source projects are now using [[Distributed version control|distributed revision control systems]], which scale better than centralized repositories such as SVN and CVS.  Popular examples are [[git]], used by the [[Linux kernel]],<ref>{{Cite web |title=The Greatness of Git - Linux Foundation |url=https://www.linuxfoundation.org/blog/blog/the-greatness-of-git |access-date=2023-08-25 |website=www.linuxfoundation.org |language=en}}</ref> and [[Mercurial]], used by the [[Python (programming language)|Python]] programming language.{{citation needed|date=November 2014}}

=== Bug trackers and task lists ===
{{Main article|Bug tracking system}}

Most large-scale projects require a bug tracking system to keep track of the status of various issues in the development of the project.

=== Testing and debugging tools ===

Since OSS projects undergo frequent integration, tools that help [[Test automation|automate testing]] during [[system integration]] are used. An example of such tool is Tinderbox. Tinderbox enables participants in an OSS project to detect errors during system integration. Tinderbox runs a continuous build process and informs users about the parts of source code that have issues and on which platform(s) these issues arise.<ref name=":0" />

A [[debugger]] is a computer program that is used to debug (and sometimes test or optimize) other programs. [[GNU Debugger]] (GDB) is an example of a debugger used in open-source software development. This debugger offers remote debugging, what makes it especially applicable to open-source software development.{{citation needed|date=November 2014}}

A memory leak tool or [[memory debugger]] is a programming tool for finding [[memory leaks]] and [[buffer overflows]]. A memory leak is a particular kind of unnecessary memory consumption by a computer program, where the program fails to release memory that is no longer needed. Examples of memory leak detection tools used by Mozilla are the [[XPCOM]] Memory Leak tools.
Validation tools are used to check if pieces of code conform to the specified syntax. An example of a validation tool is [[Splint (programming tool)|Splint]].{{citation needed|date=November 2014}}

=== Package management ===

A [[package management system]] is a collection of tools to automate the process of installing, upgrading, configuring, and removing software packages from a computer. The [[RPM Package Manager|Red Hat Package Manager]] (RPM) for .rpm and [[APT (software)|Advanced Packaging Tool]] (APT) for [[deb (file format)|.deb]] file format, are package management systems used by a number of Linux distributions.{{citation needed|date=November 2014}}

== Publicizing a project ==

Software directories and release logs:
# The [[Free Software Directory]]

Articles:
# [[Linux Weekly News]]
# IBM developerWorks

== See also ==
{{Portal|Free and open-source software}}
{{cmn|colwidth=30em|
* [[Business models for open-source software]]
* [[Government Open Code Collaborative]]
* [[Open-source software security]]
* [[Software composition analysis]]
* [[Software development process]]
* [[Release management]]
* [[Software engineering]]
* [[Metamodeling]]
}}

== References ==
{{Reflist}}

== Further reading ==
* {{Cite book |last=Kavanagh |first=Paul |title=Open source software: implementation and management |date=2004 |publisher=Elsevier Digital Press |isbn=978-1-55558-320-0 |series=Software development |location=Amsterdam Boston}}
* {{Cite book |title=Perspectives on free and open source software |date=2005 |publisher=MIT Press |isbn=978-0-262-06246-6 |editor-last=Feller |editor-first=Joseph |location=Cambridge, Mass}}
* {{Cite book |title=Free, open source software development |date=2005 |publisher=Idea Group Publ |isbn=978-1-59140-370-8 |editor-last=Koch |editor-first=Stefan |location=Hershey, Pa.}}
* {{Cite book |last=Fogel |first=Karl |url=https://www.worldcat.org/title/ocm62322583 |title=Producing open source software: how to run a successful free software project |date=2005 |publisher=O'Reilly |isbn=978-0-596-00759-1 |edition=1st |location=Beijing ; Sebastopol, CA |oclc=ocm62322583}}
* {{Cite book |last=Muir |first=Scott P. |title=Open Source Software |date=2005 |publisher=Emerald Publishing Limited |others=Mark Leggott |isbn=978-1-84544-877-6 |series=Library Hi Tech |location=Bradford}}
* {{Cite book |last=Feller |first=Joseph |title=Open Source Development, Adoption and Innovation: IFIP Working Group 2. 13 on Open Source Software, June 11-14, 2007, Limerick, Ireland |date=2007 |publisher=Springer |others=Brian Fitzgerald, Walt Scacchi, Alberto Sillitti |isbn=978-0-387-72485-0 |series=IFIP Advances in Information and Communication Technology Ser |location=New York, NY}}
* {{Cite book |url=https://www.worldcat.org/title/ocm84838909 |title=Emerging free and open source software practices |date=2008 |publisher=IGI Pub |isbn=978-1-59904-210-7 |editor-last=Sowe |editor-first=Sulayman K. |location=Hershey |oclc=ocm84838909 |editor-last2=Stamelos |editor-first2=Ioannis G. |editor-last3=Samoladas |editor-first3=Ioannis M.}}
* {{Cite book |last=Fogel |first=Karl |title=Producing Open Source Software: How to Run a Successful Free Software Project |date=2009 |publisher=O'Reilly Media, Inc |isbn=978-0-596-00759-1 |location=Sebastopol}}
* {{Cite book |last=Engard |first=Nicole C. |title=Practical open source software for libraries |date=2010 |publisher=Chandos publishing |isbn=978-1-84334-585-5 |series=Chandos information professional series |location=Oxford}}
* {{Cite book |last=Tucker |first=Allen B. |title=Software Development: An Open Source Approach |last2=Morelli |first2=Ralph |last3=de Silva |first3=Chamindra |date=2012 |publisher=Chapman and Hall/CRC |isbn=978-1-4398-1290-7 |series=Chapman and Hall/CRC Innovations in Software Engineering and Software Development Ser |location=Boca Raton}}
* {{Cite book |last=Haff |first=Gordon |title=How Open Source Ate Software: Understand the Open Source Movement and So Much More |date=2021 |publisher=Apress L. P |isbn=978-1-4842-6799-8 |edition=2nd |location=Berkeley, CA}}

== External links ==
{{Software engineering}}

{{DEFAULTSORT:Open Source Software Development}}
[[Category:Free and open-source software|Development]]