# \[ANN\] ReusePkgTemplates.jl and ReuseLicensing.jl: REUSE-compliant packages with explicit package-level licensing

**URL:** <https://discourse.julialang.org/t/ann-reusepkgtemplates-jl-and-reuselicensing-jl-reuse-compliant-packages-with-explicit-package-level-licensing/137504>\
**Category:** Package Announcements\
**Tags:** licenses, pkgtemplates, reuse\
**Created:** [June 8, 2026, 7:56pm UTC](https://discourse.julialang.org/t/ann-reusepkgtemplates-jl-and-reuselicensing-jl-reuse-compliant-packages-with-explicit-package-level-licensing/137504 "2026-06-08T19:56:29Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![gwr](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/gwr/32/33632_2.png) [@gwr](https://discourse.julialang.org/u/gwr)\
**Post date:** [June 8, 2026, 7:56pm UTC](https://discourse.julialang.org/t/ann-reusepkgtemplates-jl-and-reuselicensing-jl-reuse-compliant-packages-with-explicit-package-level-licensing/137504/1 "2026-06-08T19:56:29Z")

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# Prelude

## A typical conversation in conventional Julia package land …

> **A:** Have a look at my new package.
> 
> **B:** Nice. What’s the license?
> 
> **A:** MIT. Easy to use, easy to reuse.
> 
> **B:** MIT for what?
> 
> **A:** The package.
> 
> **B:** All of it? The code, the documentation, the documentation assets, the data …?
> 
> **A:** Yes.
> 
> **B:** That is a lot to cover for just three letters.

## … meanwhile in well-intentioned compliance-tooling land

> **R:** Look at my new package. I got you covered for reusing everything now. Every file in my repo carries a license and copyright tag. Have at it!
> 
> **S:** Wow, that’s impressive! I see a list of license expressions here: `MIT`, `CC0-1.0`, `CC-BY-4.0`, `MPL-2.0 OR EUPL-1.2`, `GPL-3.0-only`, `LicenseRef-Something` … So, what’s the package-level license?
> 
> **R:** The list is right there.
> 
> **S:** Sure. But the recipe is not the cake, is it?

Sound familiar?

We kind of “overload” a single `LICENSE` file in conventional Julia package land, while the file-level licensing done in a [REUSE](https://reuse.software)-compliant repository may leave the package licensing implicit or ambiguous.

ReuseLicensing.jl and ReusePkgTemplates.jl address that gap: they combine file-level copyright and licensing metadata in accordance with the REUSE framework, an explicit package-level license declaration in `LICENSE`, and additional machine-readable package licensing metadata in `Project.toml`.

## Easily generate REUSE-compliant packages

ReusePkgTemplates.jl provides a small convenience layer on top of PkgTemplates.jl for generating Julia packages with REUSE/SPDX licensing metadata. Generated packages include file-level copyright and licensing metadata, together with a package-level license declaration in the root `LICENSE` file.

For example:

```julia-repl
julia> using ReusePkgTemplates

julia> plugins = with_reuse(
    [   
        # your favorite PkgTemplates-plugins go here
        Git(; manifest = true, ssh = true),
        GitHubActions(; x86 = true),
        Codecov()
    ];
    package_license = "EUPL-1.2+",
    docs_license = "CC-BY-4.0",
    infrastructure_license = "0BSD",
    readme_licensing_section = true
)

julia> t = Template(; plugins)

julia> t("MyPackage")

```

This may be all that is needed to set up a package that’s REUSE-compliant from the first commit with:

- a `LICENSE` file that contains
  - the package-level copyright notice,
  - a package license expression,
  - explanatory text,
  - the license text (or texts) referenced by the license expression,

- file-level license texts in `LICENSES/`,
- REUSE annotations in `REUSE.toml` to bulk-assign licenses and copyright,
- `Project.toml` licensing metadata,
- a README licensing section,
- a REUSE lint workflow when `GitHubActions()` is used.

See the [documentation](https://bsl-support.de/julia/ReusePkgTemplates.jl/) for more information.

## Change package license expressions or package copyright notices coherently

ReuseLicensing.jl provides the core licensing machinery used by ReusePkgTemplates.jl. It parses SPDX license expressions, works with checked-in SPDX License List data, consumes `reuse lint` output, and validates package-level licensing metadata for Julia packages.

It can also update package-level license expressions or copyright notices coherently, so that `LICENSE` and `Project.toml` metadata stay aligned.

To check SPDX license expressions, you could for example do:

```julia-repl
julia> using ReuseLicensing

julia> parsed = parse_spdx_expression("MIT OR Apache-2.0");

julia> has_approved_license_path(parsed, OSIApproved())
true

julia> has_approved_license_path("MIT AND LicenseRef-Internal", ValidSPDX())
true

```

See the [documentation](https://bsl-support.de/julia/ReuseLicensing.jl/) for more information.

Comments, criticism, and issue reports are warmly appreciated.

* * *

#### A personal remark on licensing policy

Nothing requires you to use a copyleft license like the [European Union Public Licence](https://interoperable-europe.ec.europa.eu/collection/eupl) (`EUPL-1.2`): in the example above, `package_license = "MIT"` works just as well, if that’s what you want for your package. (The `0BSD` license used in the example is even more permissive than `MIT`.)

At the same time, permissive licensing should not be mistaken for being automatically “in everybody’s best interest.” For publicly funded software or for infrastructure software, copyleft licensing can be a rational policy choice: it helps preserve the public value of a work and it avoids turning public investment into a subsidy for incumbent market players. The gains from permissive licensing are not necessarily evenly distributed.

See the essay by [Lawrence Lessig](https://courses.cs.duke.edu/common/compsci092/papers/open/lessig-opensource.pdf) (2002) on “_Open Source Baselines: Compared to What?_”

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<div class="post-metadata">

**Author:** ![gwr](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/gwr/32/33632_2.png) [@gwr](https://discourse.julialang.org/u/gwr)\
**Post date:** [October 8, 2026, 12:30pm UTC](https://discourse.julialang.org/t/ann-reusepkgtemplates-jl-and-reuselicensing-jl-reuse-compliant-packages-with-explicit-package-level-licensing/137504/2 "2026-10-08T12:30:49Z")

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A quarter year has passed since release and looking back at the hesitance of Julians to adapt “my approach” (maybe it is just REUSE-aversion?) I find that some clarifying remarks on package-level vs. file-level licensing are in order.

[Debian’s machine-readable copyright specification (5.1)](https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/#header-stanza) can be seen as a very close and useful precedent. It allows package-level license information to complement (but not replace) file-level information, including clarification of redistribution terms for combinations of differently licensed material.

Within our community, FFTW.jl 's License section in the `README.md` illustrates a related concern: its bindings are MIT-licensed, while the backend has its own licensing terms, with consequences for distributing a combined work.

ReusePkgTemplates.jl, supported by ReuseLicensing.jl, distinguishes an author-maintained outbound package-level declaration from authoritative REUSE file-level information. That declaration does _not override_ individual file licenses or relicense dependencies.

My policy position is that authors (more precisely: copyright holders) should choose that declaration with the package’s intended operation and expected dependencies in mind. Authors are especially well placed to explain how components interact. This does _not imply_ any guarantee of license compatibility across every possible dependency resolution.

The practical aim is to make these distinctions explicit and maintainable when creating Julia packages. Further explanations can be found in the FAQ.

P.S. I’m planning monorepo support for ReusePkgTemplates.jl: generating multiple Julia packages within one repository, with consistent REUSE metadata and explicit package-level licensing declarations.