Open core
Licensing
Reach and commercial viability usually pull against each other. Open core is the structure that reconciles them without relicensing anyone's contribution.
Source of record: LICENSING.md in the Bivdi repository.
The model#
| Component | Licence | Why |
|---|---|---|
| Specification | Freely implementable | Anyone may write a conforming implementation. An open standard is worth more than a closed one. |
| SDKs, libraries, ABI headers | MIT OR Apache-2.0 | Maximum adoption. Dual-permissive is compatible with both GPLv2-only and GPLv3, so nothing is shut out. |
| Bivdi's own core — services, drivers, kernel code Bivdi writes | MPL-2.0 | Weak, file-level copyleft. Modifications to Bivdi's own files come back; applications are not affected. Low enterprise friction, OSI-approved, GPL-compatible. |
| Third-party components | Their own licences | Bivdi cannot relicense or sell what it does not own. |
| Documentation | CC BY 4.0 | Docs are for reading and reuse, with attribution. |
| Commercial / enterprise layer | Proprietary | Management console, attestation service, certified builds, support, closed value-add features. |
No CLA — a DCO instead#
Bivdi uses a Developer Certificate of Origin sign-off, not a Contributor Licence Agreement.
A CLA raises the barrier to contributing and signals single-vendor control. It exists so that a company can relicense contributed code later. Under open core there is nothing to relicense: the open part stays open, and revenue comes from proprietary layers that live alongside it rather than from selling exceptions to the licence.
Why not AGPL#
AGPL plus a CLA is the other common answer, and it fails on the same axis twice. AGPL is banned outright in many regulated and enterprise environments — which are precisely the environments a capability-secure operating system is built for. And the CLA that usually accompanies it costs contributions.
The seL4 boundary#
If the microkernel choice resolves to seL4, it enters as a third-party component under its own licence, never as part of Bivdi's licensed core and never resold. The seL4 kernel is GPLv2-only; its userland libraries are BSD-licensed, and components that interact with the kernel through syscalls are not derivative works of it.
One rule is absolute and applies regardless of which kernel is chosen:
Linux kernel driver code is GPLv2-only and must never be copied into Bivdi's own MPL-2.0 components. Reuse of Linux drivers happens only inside an isolated driver VM, across a protocol boundary. No dependency whose licence conflicts with this may be introduced.
Provenance of authorship#
All committed code is human-reviewed and edited before it lands, the provenance of authorship is documented, and purely machine-generated code is not placed in the proprietary commercial layer.
This website#
The site's content follows the documentation licence, CC BY 4.0. Its source is public.