LPI OSS Essentials flashcards

39 cards. Read the term and the definition here. The deck at the top of this page is optional.

Source code

Human-readable program instructions written in a programming language. It must be compiled or interpreted before the machine can execute it, and it is what open source licenses make available.

Four freedoms

The Free Software Foundation's criteria: run the program for any purpose, study and modify it, redistribute copies, and distribute modified versions. Access to source code is a precondition.

Copyleft

A licensing technique that requires redistributed derivative works to keep the same license terms. It uses copyright law to keep software and its modifications open rather than to restrict them.

Package manager

A tool that installs, upgrades, and removes software while resolving dependencies and verifying package signatures. Examples include apt, dnf, pacman, and zypper on Linux distributions.

Semantic versioning

A MAJOR.MINOR.PATCH numbering convention: MAJOR for incompatible API changes, MINOR for backward-compatible features, PATCH for backward-compatible bug fixes. It lets consumers judge upgrade risk.

Distribution

A curated bundle of the Linux kernel, userland utilities, an init system, a package manager, and default configuration. Examples include Debian, Fedora, and Arch.

Reproducible build

A build process that yields bit-identical binaries from the same source and toolchain. It lets independent parties verify that distributed binaries match published source code.

Proprietary software

Software whose license restricts copying, modification, and redistribution, typically with source withheld. Users cannot audit or fork it, and vendor lock-in risk is higher.

MIT license

A short permissive license requiring only preservation of the copyright and permission notice. It permits relicensing of derivative works under other terms, including proprietary ones, and is GPL-compatible.

GPL

The GNU General Public License, a strong copyleft license. Distributing derivative works requires releasing them under the GPL and providing source; private use triggers no obligation.

LGPL

The GNU Lesser General Public License, a weak copyleft license. Proprietary programs may link against LGPL libraries if users can replace the library and relink the application.

AGPL

The Affero GPL, a strong copyleft license whose obligations also trigger when users interact with the software over a network. It targets the software-as-a-service loophole.

Apache License 2.0

A permissive license that adds an express patent grant and a patent retaliation clause. Redistributors must retain notices and state changes made to the files.

License compatibility

The property that code under two licenses can be combined and distributed lawfully. Permissive code usually fits into copyleft projects; conflicting copyleft terms may be incompatible.

Open Source Definition

The OSI's ten criteria a license must meet, covering free redistribution, source availability, derived works, integrity of authorship, no discrimination, and technology neutrality.

CC BY

A Creative Commons license requiring only attribution. Others may share and adapt the work, including commercially, provided they credit the creator and indicate changes.

CC BY-SA

A Creative Commons license combining attribution with share-alike. Adaptations must be distributed under the same or a compatible license, so downstream reuse stays open.

CC BY-NC

A Creative Commons license that forbids commercial use. Because 'commercial' is legally undefined, many organizations avoid NC material, limiting adoption and remixing.

CC BY-ND

A Creative Commons license permitting redistribution of verbatim copies with attribution but forbidding distribution of modified versions. It therefore blocks remixing and adaptation.

CC0

A public domain dedication waiving copyright to the extent law allows, with no attribution condition. It is a waiver rather than a license and is often used for data.

Creative Commons attribution

Credit must name the creator, cite the license, link to the source, and note whether changes were made. All Creative Commons licenses from version 4.0 are irrevocable once granted.

Open educational resources

Teaching and learning materials released under open licenses so they can be reused, revised, remixed, and redistributed. CC BY and CC BY-SA are common choices.

ODbL

The Open Database License, a share-alike license for databases. It requires attribution and keeps derived databases open, and it is used for OpenStreetMap data.

Open core

A business model offering a free community edition under an open source license plus paid proprietary features, enterprise add-ons, or managed hosting for paying customers.

Dual licensing

Offering the same code under both a copyleft license for free and a proprietary license for a fee. It requires the vendor to own or control all copyrights.

Support and services model

Revenue from service level agreements, consulting, training, and integration around freely available software. The software itself is given away to maximize adoption.

Hosted SaaS model

The vendor runs open source software for customers and charges for operations, uptime, security patching, and convenience. The underlying code stays publicly available.

Relicensing risk

The danger that a project tightens its license after wide adoption, prompting community forks. Adopters assess governance and copyright ownership before committing.

Trademark as moat

Code can be forked, but project names and certification marks cannot. Vendors therefore build brand and compatibility programs around names they control.

Foundation stewardship

Transferring project assets and governance to a neutral foundation such as the Apache Software Foundation or Linux Foundation. It reduces single-vendor control and adopters' risk.

Bus factor

The number of contributors who must disappear before a project stalls. Documented processes, shared credentials, and multiple maintainers raise it and reduce risk.

CONTRIBUTING file

A repository document explaining how to report bugs, propose changes, run tests, and submit patches. It sets expectations and reduces maintainer overhead from drive-by contributions.

Issue tracker

A system recording bugs, feature requests, and tasks with labels, milestones, and assignees. It provides public triage and a searchable record of project decisions.

Release branch

A branch cut from main to stabilize a specific version while development continues elsewhere. Fixes are applied there and merged back, isolating release risk.

Pull request review

A public code review workflow where contributors propose changes and maintainers comment before merging. The discussion becomes part of the project's technical record.

Mailing list archive

A searchable public record of project discussion and decisions. Many projects treat it as the canonical rationale for design choices, long after chat threads vanish.

Developer Certificate of Origin

A per-commit sign-off stating the contributor has the right to submit the code under the project's license. It is a lighter alternative to a contributor license agreement.

Asynchronous communication

Discussion that does not require participants to be online simultaneously, such as email, forums, and issue comments. It accommodates time zones and preserves a written record.

Forking

Copying a project's code and history to develop independently. It is a normal open source right, and forks sometimes later merge improvements back upstream.