# Open Source Open Source refers to software whose source code is made publicly available for anyone to view, modify, and distribute. The term was coined in 1998 by [[Christine Peterson]] and popularized by [[Eric S. Raymond]], [[Bruce Perens]], and others who founded the [[Open Source Initiative (OSI)]]. They sought a more business-friendly alternative to [[Richard Stallman]]'s "free software" terminology. While open source shares practical similarities with free software, the philosophies differ: open source emphasizes practical benefits (better code quality, collaboration, transparency), while free software emphasizes ethical freedoms. [[Richard Stallman]] considers open source a dilution of the free software message. Despite this tension, both movements have driven the collaborative development model that powers much of modern software infrastructure. ## Open Source Definition (OSD) The OSI defines open source through criteria including: - **Free redistribution**: No royalty or fee restrictions - **Source code**: Must be included or easily obtainable - **Derived works**: Modifications and distribution allowed - **No discrimination**: Against persons, groups, or fields of endeavor - **License distribution**: Rights apply to all recipients ## Common Open Source Licenses | License | Type | Notable Users | | ---------------------- | ------------- | ----------------------- | | [[MIT License]] | Permissive | React, Node.js, VS Code | | [[Apache 2.0 License]] | Permissive | Android, Kubernetes | | [[GPLv3 License]] | Copyleft | Linux kernel, WordPress | | [[BSD License]] | Permissive | FreeBSD, PostgreSQL | | MPL 2.0 | Weak copyleft | Firefox, Thunderbird | ## References - https://opensource.org - https://opensource.org/osd - Eric S. Raymond: *The Cathedral and the Bazaar* ## Related - [[Free and Open Source Software (FOSS)]] - [[Richard Stallman]] - [[Free Software Foundation (FSF)]] - [[GNU is not Unix (GNU)]] - [[Linux]] - [[Git]] - [[GNU General Public License (GPL)]] - [[GPLv2 License]] - [[GPLv3 License]] - [[Affero General Public License (AGPL)]] - [[LGPL License]] - [[Apache 2.0 License]] - [[BSD License]] - [[MIT License]]