Can you use open-source software for business? Licences in plain English
"Free" and "open source" don't mean "do what you like". The licence decides what you can do, and the differences matter once money is involved.
Permissive licences: MIT, Apache-2.0, BSD
You can use the software, change it, and sell work made with it, including inside a paid product. The main condition is keeping the copyright notice. Apache-2.0 also gives you a patent grant. These are the easiest to build a business on.
GPL: share alike when you pass it on
You can use it freely, including for client work. If you give copies of the software, or a changed version, to other people, they must get the source under the same licence. Using it yourself, or running it for a client on your own server, usually doesn't trigger that.
AGPL: the network clause
AGPL is GPL with one extra rule: if people use your changed version over a network, such as a hosted web app, you must offer them the source of your changes. Running the unmodified software for a client is generally fine. Changing it and selling access to it as a service means sharing your changes. Many tools we list, such as Docmost, Grafana and listmonk, use AGPL.
Weak copyleft: MPL-2.0
Only changes to the licensed files have to stay open. The rest of your product can stay closed. Penpot uses MPL-2.0.
Source-available is not open source
Licences such as Elastic and BSL let you read the code but limit what you can do with it, often by banning you from selling it as a hosted service. Invoice Ninja uses the Elastic licence, for example. Check the exact terms.
Mixed licences
Some projects are open source in the main folder and commercial in another, often called "enterprise" or "ee". The paid parts need a licence from the maker. Our tool pages flag these under "Things to check".
A quick check before you build on something
- Find the licence file in the repository and read the first page.
- Look for an enterprise or commercial folder.
- If you will host it for others, check what the licence says about network use.
- Keep the copyright notices.
Not legal advice. Read each project's licence file before you build or sell anything on it.