Open Source Technology Cheatsheet

Cheatsheet Content

1. What is Open Source? Definition: Software with source code made available under a license that allows users to study, change, and distribute the software to anyone and for any purpose. Key Principles: Free Redistribution Source Code Availability Derived Works Integrity of The Author's Source Code No Discrimination Against Persons or Groups No Discrimination Against Fields of Endeavor Distribution of License License Must Not Be Specific to a Product License Must Not Restrict Other Software License Must Be Technology-Neutral 2. Common Open Source Licenses Licenses dictate how open source software can be used, modified, and distributed. License Type Description Key Requirements Permissive (e.g., MIT, Apache 2.0, BSD) Minimal restrictions on use and redistribution. Often only requires attribution. Retain copyright notice Include license text No warranty Copyleft (e.g., GPL, LGPL) Requires derivative works to be licensed under the same or compatible terms. "Viral" nature. Retain copyright notice Include license text Distribute source code of modified versions Modified works must use same license 3. Benefits of Open Source Cost-Effectiveness: Often free to use, reducing software acquisition costs. Flexibility & Customization: Source code can be modified to meet specific needs. Security: "Many eyes" principle; bugs and vulnerabilities are often found and fixed faster. Quality: Collaborative development can lead to higher quality and more robust software. Transparency: Code is open for inspection, fostering trust and understanding. Innovation: Builds upon existing projects, accelerating development and fostering new ideas. Community Support: Large communities provide peer support, documentation, and plugins. Vendor Neutrality: Avoids vendor lock-in; users are not tied to a single provider. 4. Popular Open Source Technologies Operating Systems Linux: Kernel (Ubuntu, Fedora, Debian, Android) FreeBSD: Unix-like OS Programming Languages Python: General-purpose Java (OpenJDK): Enterprise applications JavaScript (Node.js): Web development PHP: Web development R: Statistical computing Databases MySQL: Relational database PostgreSQL: Advanced relational database MongoDB: NoSQL document database Redis: In-memory data store Web Servers & Development Apache HTTP Server: Dominant web server Nginx: High-performance web server, reverse proxy Git: Distributed version control system Docker: Containerization platform Kubernetes: Container orchestration WordPress: Content Management System (CMS) Joomla!: Content Management System (CMS) Cloud & Big Data Apache Hadoop: Distributed processing of large data sets Apache Spark: Unified analytics engine for big data OpenStack: Cloud computing platform 5. Contributing to Open Source Find a Project: Look for projects on GitHub, GitLab, SourceForge, or specific community sites. Choose a project aligned with your skills and interests. Start Small: Report bugs. Improve documentation (typos, clarity, examples). Suggest minor features or fixes. Look for "good first issue" or "help wanted" tags. Understand the Workflow: Fork the repository. Clone locally. Create a new branch for your changes. Make changes. Commit changes with descriptive messages. Push to your fork. Open a Pull Request (PR) or Merge Request (MR) to the original project. Communication: Read the project's contribution guidelines. Engage with the community (mailing lists, forums, chat). Be polite and open to feedback on your contributions. 6. Open Source Development Models Bazaar Model: Decentralized, collaborative development. Many developers, often geographically dispersed. Rapid iteration, frequent releases. Example: Linux kernel development. Cathedral Model: Centralized development, typically by a small group or single entity. Structured, controlled releases. Example: Early GCC development. 7. Governance Models Benevolent Dictator For Life (BDFL): A single individual makes final decisions (e.g., Python's Guido van Rossum). Meritocracy: Decisions are made by contributors based on their demonstrated merit and contributions. Consensus: Decisions reached through agreement among a group of core developers. Foundation-backed: A non-profit foundation oversees the project (e.g., Apache Software Foundation).