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permalink: /community/
redirect_from: /existing/
title: Existing projects and communities
---

If you're contributing to or extending an existing project, it's almost always easiest to continue using that project's license. To find its license, look for a file called `LICENSE` or `COPYING`, and skim the project's `README`. If you can't find a license, [ask the maintainers](/no-permission/#for-users).

Depending on the original project's license, using the same license might be a requirement, not just the easiest thing to do. (See the "same license" condition of [some licenses](/licenses/).)

Some communities have strong preferences for particular licenses. If you want to participate in one of these, it will be easier to use their preferred license, even if you're starting a brand new project with no existing dependencies. Some examples include:

{: .bullets}

* [Apache](https://www.apache.org/licenses/) requires [Apache License 2.0](/licenses/apache-2.0/)
* [Cloud Native Computing Foundation](https://github.com/cncf/foundation/blob/main/charter.md#11-ip-policy) requires [Apache License 2.0](/licenses/apache-2.0/)
* [GNU](https://www.gnu.org/licenses/license-recommendations.html) recommends [GNU GPLv3](/licenses/gpl-3.0/) for most programs
* [npm packages](https://libraries.io/search?platforms=npm) overwhelmingly use the [MIT](/licenses/mit/) or the very similar [ISC](/licenses/isc) licenses
* [OpenBSD](https://www.openbsd.org/policy.html) prefers the [ISC License](/licenses/isc/)
* [Rust](https://rust-lang.github.io/api-guidelines/necessities.html#crate-and-its-dependencies-have-a-permissive-license-c-permissive) crates are overwhelmingly licensed [MIT](/licenses/mit/) [`OR`](https://spdx.github.io/spdx-spec/v2.3/SPDX-license-expressions/#d42-disjunctive-or-operator) [Apache License 2.0](/licenses/apache-2.0/)
* [WordPress](https://wordpress.org/about/license/) plugins and themes must be [GNU GPLv2](/licenses/gpl-2.0/) (or later)
* [Joomla](https://tm.joomla.org/joomla-license-faq.html#can-i-release-an-extension-under-a-non-gpl-license) extensions and templates must be [GNU GPLv2](/licenses/gpl-2.0/) for the PHP code.

Communities come in all shapes and sizes, and more than one community might be pertinent (e.g., keep in mind [your company](https://opensource.guide/legal/#what-does-my-companys-legal-team-need-to-know) if you work for one). The examples above are *very* well established. If the community you're building a project for doesn't have set-in-stone licensing traditions, or you don't see your project as part of any particular community, that's fine: [make your own choice of an open source license](/).