ADR-0001: License#

• Status: Accepted
• Date: 2026-10-01

Context#

OLS CAD wants (a) the core to stay open and improvements to flow back, and (b) utilities and consultancies to be able to write in-house or commercial plugins without being forced to publish them.

Options considered#

1. Apache-2.0 — permissive, patent grant, maximum industry adoption; improvements to the core may stay closed.
2. MPL-2.0 — file-level copyleft: changes to OLS CAD files must be shared, but plugins/separate files can have any license. Patent grant.
3. LGPL-3.0 — library copyleft; awkward with Python packaging and static linking of Rust kernels.
4. GPL-3.0 — strong copyleft; would likely deter proprietary plugins and utility adoption.

Recommendation#

MPL-2.0 for the core packages (improvements to the core come back, plugins stay free to choose), optionally Apache-2.0 for ols-sdk and plugin templates.

Decision#

MPL-2.0 for the whole repository (accepted 2026-10-01). The core stays open — modifications to OLS CAD files must be shared — while plugins in separate files may use any license, including proprietary. Revisiting Apache-2.0 for ols-sdk/plugin templates remains possible later.