# open-source software

> software that anyone is free to use and redistribute in its current state with a permissive licence giving a libre access to its original source code (but not necessarily to modify it)

**Wikidata**: [Q1130645](https://www.wikidata.org/wiki/Q1130645)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Open-source_software)  
**Source**: https://4ort.xyz/entity/open-source-software

## Summary
Open-source software (OSS) is software that anyone is free to use and redistribute. It is released under a permissive license that provides libre access to its original source code. While users can freely access the code, the license does not necessarily grant the right to modify it.

## Key Facts
- **Core Principle:** Provides users with free access to its original source code under a permissive license.
- **User Rights:** Anyone is free to use and redistribute the software in its current state.
- **Classification:** It is a subclass of source-available software, freely redistributable software, and open content.
- **Primary Characteristic:** A key characteristic of open-source software is its use of a free license.
- **Conceptual Opposite:** It is considered the opposite of proprietary software.
- **Relationship to Similar Terms:** The term is described as being both different from and the same as "free software" and "free and open-source software."
- **Prominent Examples:** Notable examples include the Android operating system, the utility-first CSS framework Tailwind CSS, the video editing library MoviePy, and the Subversion client TortoiseSVN.
- **Community Presence:** The topic has a dedicated English-language subreddit (r/OpenSource) and a Stack Exchange site at opensource.stackexchange.com.

## FAQs
### Q: What is the main difference between open-source and proprietary software?
A: Open-source software provides access to its source code and allows free use and redistribution under a permissive license. It is considered the direct opposite of proprietary software, which typically restricts access to the source code and limits use and redistribution.

### Q: Can I modify open-source software?
A: Not necessarily. While the license provides access to the software's original source code, it does not automatically grant the right to modify it.

### Q: Is open-source software the same as free software?
A: The relationship is complex. The provided data indicates that open-source software is considered different from free software, but is also said to be the same as free software, reflecting different definitions and philosophies.

## Why It Matters
Open-source software is a foundational component of modern technology and the concept of "open knowledge." By providing free access to source code, it fosters a global environment of collaboration, transparency, and innovation that stands in contrast to the closed model of proprietary software. This approach has enabled the creation of a vast ecosystem of powerful, free tools that are critical to individuals, corporations, and research institutions.

The impact of OSS is widespread, powering everything from global mobile operating systems like Android to essential developer tools like mitmproxy and scientific research projects like Einstein@Home. It lowers the barrier to entry for developers and organizations, allowing them to build upon existing work rather than starting from scratch. The existence of dedicated online communities on platforms like Reddit and Stack Exchange further highlights its collaborative nature, where knowledge and improvements are shared freely. This model has become a cornerstone of the digital infrastructure, underpinning countless applications, web services, and technological advancements.

## Notable For
- **Source Code Accessibility:** Its defining trait is providing "libre access" to its original source code, which distinguishes it from closed-source, proprietary software.
- **Permissive Licensing:** It is characterized by the use of a free, permissive license that grants anyone the right to use and redistribute the software.
- **Broad Applicability:** Open-source software is not limited to one domain; examples span mobile operating systems (Android, CalyxOS), web development (Tailwind CSS), scientific computing (DeepLabCut), 3D modeling (Blockbench), and video games (Beyond All Reason).
- **Conceptual Ambiguity:** The term is simultaneously described as being different from and the same as "free software" and "free and open-source software," highlighting ongoing definitional distinctions within the field.

## Body
### ### Definition and Core Principles
Open-source software (OSS) is defined as software that anyone is free to use and redistribute in its current state. This freedom is granted through a permissive license that gives users "libre access" to the original source code. However, this access to the source code does not inherently include the right to modify it.

### ### Classification and Relationships
In knowledge taxonomies, open-source software is categorized as a component of "open knowledge" and a subclass of "source-available software," "freely redistributable software," and "open content." It is positioned as the direct opposite of "proprietary software."

Its relationship with similar terms is noted as complex. The source material indicates that OSS is considered "different from" concepts like free software, OSI-approved licenses, and free and open-source software (FOSS). At the same time, it is also "said to be the same as" free software and FOSS, reflecting a lack of universal consensus on the exact boundaries of these terms.

### ### Examples Across Diverse Fields
The provided data lists numerous examples of open-source software, demonstrating its wide-ranging application:
- **Operating Systems:** Android, CalyxOS
- **Developer Tools:** pythontesseract, pipreqs, pendulum, MoviePy, arrow, flashtext (python package), Tailwind CSS, Semgrep, mitmproxy
- **User Applications:** Snap! (programming language), BizHawk (emulator), wxMaxima (graphical interface), Blockbench (3D modeling), Kibi (text editor), TortoiseSVN (Subversion client)
- **Platforms and Services:** HOT Tasking Manager, Odysee (video hosting), Pi-KVM (KVM over IP)
- **AI and Machine Learning:** DeepLabCut, Ray, EleutherAI, Feast, NSFW Filter
- **Scientific and Data Management:** Einstein@Home, Curator, Social Feed Manager, openlibm

### ### Representation in Knowledge Bases
Open-source software is a well-documented entity across numerous databases and thesauri. It has assigned identifiers in systems including:
- **Academic & Technical:** ACM Classification Code (10003597), ANZSRC FOR ID (080306), ScienceDirect Topic ID (computer-science/open-source-software)
- **Library & Archival:** EuroVoc (435299), UNESCO Thesaurus (concept17094), Art & Architecture Thesaurus (300387513), National Diet Library Authority ID (01148004)
- **General Knowledge Bases:** Freebase (/m/01pjyj), Golden (Open-source_software-RGV84), Kbpedia (OpenSourceIBT)

## Schema Markup
```json
{
  "@context": "https://schema.org",
  "@type": "Thing",
  "name": "open-source software",
  "description": "Open-source software is software that anyone is free to use and redistribute, with a permissive license providing access to its original source code.",
  "sameAs": [
    "https://en.wikipedia.org/wiki/Open-source_software",
    "https://golden.com/wiki/Open-source_software-RGV84"
  ],
  "additionalType": [
    "source-available software",
    "freely redistributable software",
    "open content"
  ]
}

## References

1. Freebase Data Dumps. 2013
2. [Source](http://data.loterre.fr/ark:/67375/TSO-TRTL77DD-T)
3. BBC Things
4. Quora
5. [Source](https://www.abs.gov.au/AUSSTATS/abs@.nsf/DetailsPage/1297.02008?OpenDocument)
6. [Source](https://golden.com/wiki/Open-source_software-RGV84)
7. KBpedia
8. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)
9. [Community not found / Twitter](https://twitter.com/i/communities/1471569662462726147)
10. Wikibase TDKIV