MD-OS (Artificial Prefrontal Cortex) is distributed under the GNU General Public License version 2 only, identified by:
SPDX-License-Identifier: GPL-2.0-only
The complete license and repository application notice are in ../LICENSE.
The original project was created by Alessandro Rizzo. Contributors retain copyright in their own contributions unless a separate written agreement says otherwise. See ../AUTHORS.md and ../CONTRIBUTING.md.
Unless a file or component carries a different notice, GPL-2.0-only is the default license for repository-original source code, natural-language programs, schemas, knowledge models, documentation, examples, tests, build scripts, and other source artifacts distributed as part of MD-OS.
The default does not erase or replace:
Third-party and externally sourced material must retain its own notices and must not be represented as relicensed merely because it is stored near or processed by MD-OS.
Running MD-OS does not make every output GPL automatically. GPLv2 itself states that program output is covered only when its contents constitute a work based on the program. That determination depends on the actual content and applicable law.
In particular, no automatic ownership or relicensing claim is made over:
md-os/ops/local/.Generated artifacts that reproduce or adapt protected MD-OS source may remain subject to GPL-2.0-only. Distribution decisions must preserve provenance and applicable third-party terms.
MD-OS is not a kernel and does not copy Linux’s syscall exception. The current license grants no special linking, plugin, connector, protocol, API, or host-runtime exception.
Communication with MD-OS does not receive a blanket legal classification in this policy. Whether a connector or external program is independent, aggregated, combined, or derivative depends on how it is designed and distributed. A future stable interface exception or permissively licensed SDK must be proposed explicitly, reviewed for compatibility, and verified before publication.
Earlier copies of this repository were offered under the MIT License. This policy applies to the current 5.0.1 source distribution and future covered contributions accepted under it. It does not revoke permissions already received for historical MIT-licensed copies.
When material from an earlier MIT-licensed copy remains identifiable, preserve its applicable historical copyright and permission notice when required. A recipient may not assume that later GPL-covered changes are also available under the historical MIT terms.
MD-OS uses the Developer Certificate of Origin 1.1 rather than mandatory copyright assignment. Each contribution must include:
Signed-off-by: Full Name <email@example.com>
The sign-off certifies the contributor’s right to submit the contribution under the indicated open-source license. See ../DeveloperCertificateOfOrigin.txt.
GPLv2 requires preservation of appropriate copyright and license notices when covered work is distributed. The preferred project-level citation is defined in ../CITATION.cff.
Copyright, citation, governance, and project-name policy are separate:
LICENSE grants copyright permissions and imposes copyleft conditions;AUTHORS.md records original creation and contributor ownership;CITATION.cff provides scholarly and project citation metadata;GOVERNANCE.md identifies the official mainline and integration process;TRADEMARKS.md addresses truthful project identification without
restricting GPL software freedoms.The legal and engineering model intentionally combines distinct lessons:
UNIX decomposition
+ Linux-style GPL reciprocity and open contribution
+ BSD-style coherent base-system evolution
+ APFC policy, scheduling, inhibition, verification, and readback
= MD-OS agentic Operating Filesystem
BSD-style coherence is an architectural discipline here, not a statement that MD-OS uses a BSD license.
This document describes the project’s intended licensing policy. It is not legal advice and does not replace the controlling license text or applicable law.