Open Source

• aka Open Source Software (OSS)
• The source code is publicly viewable, modifiable, and distributable under an established license recognized by the Open Source Initiative (OSI)

Open Source History

Year	Event
1970s–1980s	Microsoft, IBM started selling closed-source software
1985	Free Software Movement by Richard Stallman; GPL License created in 1989
1992	Linux kernel by Linus Torvalds released under GPL
1998	Open Source Initiative (OSI) founded; Promoted the term “Open Source” as business-friendly
2000s	Linux, Apache, MySQL, PHP, Perl (LAMP) stack powered millions of websites
2005	Git created by Linus Torvalds
2008	GitHub launched

Free Software Movement

• Richard Stallman started it in 1983
• He founded Free Software Foundation (FSF)
• He created GNU project
• Released the GPL License - ensures derivatives remain free/open

Source Available

• Code is public and viewable for auditing, but the license strictly prohibits commercial deployment, modification, or hosting it as a competing cloud service
• Examples:
  • Redis
  • Elasticsearch

Open Governance

• Project roadmaps, feature approvals, and trademarks are controlled by a neutral, non-profit foundation
• These foundations are funded and staffed by private, for-profit corporations protecting their own commercial interests
• Examples:
  • Linux Foundation
  • Eclipse Foundation

Open Core

• aka Freemium
• Core application code is open-source, but production-critical enterprise features are locked behind a proprietary commercial license
• Example
  • GitLab

Commercial OSS

• aka COSS
• Software is distributed for free to quickly gain market share and developer adoption
• Monetized via enterprise support subscriptions, paid SLAs, and managed cloud hosting once it becomes an industry standard
• Examples:
  • Spring Boot
  • RHEL by RedHat
  • Rancher by SUSE
  • Confluent Kafka

Single Vendor OSS

• A project published under a fully free, open-source license, but where a single commercial company retains absolute control over the repository, roadmaps, and trademarks
• Outside contributors are usually required to sign a Contributor License Agreement (CLA), passing copyright back to the controlling corporation.
• Examples
  • Android (Google)
  • Flutter (Google)

Dual Licensing

• A single copyright holder simultaneously publishes the exact same codebase under two different licenses
• Free under a strong copyleft license and requires a paid commercial license to bypass copyleft terms and keep derivative code private
• Example: MySQL

Open Wash

• A marketing tactic where a company brands a product as “open” to win community adoption while keeping absolute private control over its core architecture
• Example: OpenAI

Open Data

• Datasets that are freely available for anyone to access, reuse, and redistribute without proprietary or copyright restrictions
• In AI, it requires the raw training corpus to be public for full replication and auditing, which remains rare due to corporate legal and privacy liabilities
• Examples
  • Wikipedia Data
  • Common Crawl Data

Open Weights

• An AI model where the final trained parameters are released publicly, allowing users to download, run, and fine-tune the neural network on local infrastructure
• Training data, data curation pipelines, and foundational training code are kept secret
• Examples
  • Meta Llama
  • Mistral