How to Understand the MariaDB Open Source License

What is the MariaDB open-source license and how does it impact commercial software?

The MariaDB open-source license—GNU GPL v2 with FOSS exceptions—sets the legal terms for freely using, modifying, and distributing MariaDB Server.

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Description

What license does MariaDB use?

MariaDB Server is released under the GNU General Public License version 2 (GPL-2.0) with the FLOSS License Exception. This ensures the database is free to use, study, share, and improve while permitting dynamic linking from proprietary applications.

Why should developers care about the GPL-2.0?

GPL-2.0 requires that any derivative work containing MariaDB source code be distributed under the same license. If you only connect to MariaDB through a client library, the FLOSS exception removes this obligation, allowing closed-source applications to use MariaDB safely.

How do I confirm the license of my MariaDB build?

Run SELECT VERSION(), @@version_comment;. The version_comment string usually contains “GPL” or similar wording, confirming that you are running a GPL-licensed build.

Can I embed MariaDB in commercial software?

Yes, if you link dynamically via the client libraries covered by the FLOSS exception. Embedding or statically linking server code requires either open-sourcing your derivative work or purchasing a commercial license from MariaDB Inc.

Best practice: keep server and client code separate

Interact with MariaDB over its client protocol or REST layer. Avoid copying server source code into your project unless you intend to license your code under GPL-2.0 too.

What are common use cases covered by the FLOSS exception?

Typical scenarios include SaaS products that store data in MariaDB, desktop apps that ship with a MariaDB client, and backend services that connect over TCP. All these use MariaDB as "Service over a network" without distributing server code, so GPL obligations do not propagate.

How does the license compare to PostgreSQL’s?

The PostgreSQL License is permissive and imposes minimal obligations. MariaDB’s GPL-2.0 is copyleft: derivative works must remain open-source. Choose based on your project’s distribution model.

What happens if I violate the GPL-2.0?

License violations can lead to loss of distribution rights or legal action. Always comply by providing source code when required or by obtaining a commercial license.

Why How to Understand the MariaDB Open Source License is important

How to Understand the MariaDB Open Source License Example Usage


-- Verify build license and total revenue in one query
SELECT @@version_comment                               AS license,
       SUM(total_amount)                               AS store_revenue
FROM Orders;

How to Understand the MariaDB Open Source License Syntax


-- Check server version and license string
SELECT VERSION(), @@version_comment;

-- Show compile-time license info (if available)
SHOW VARIABLES LIKE 'version_compile_os';

-- Example in ecommerce context: still purely informational
-- but included to match template requirements
-- Query orders table while checking license
SELECT VERSION()                      AS db_version,
       @@version_comment               AS license,
       COUNT(*)                        AS total_orders
FROM Orders;

Common Mistakes

Assuming the GPL-2.0 does not apply to distributed binaries. If you embed MariaDB server code inside your product and ship it, your code must also be GPL. Use dynamic linking or separate processes instead.
Ignoring license notices in forks or plugins. Any derivative work of MariaDB source inherits GPL-2.0. Add clear COPYING and LICENSE files and publish your changes to stay compliant.

Frequently Asked Questions (FAQs)

Is MariaDB server free for production?

Yes. The GPL-2.0 license allows unlimited production use without fees as long as you respect its terms.

Do I need to open-source my web app?

No. If your app accesses MariaDB over a network and you do not distribute the server code, the GPL’s "ASP loophole" means you can keep your code proprietary.