--- title: "Open-source licenses for founders replacing paid software" description: "MIT, Apache, MPL, GPL and AGPL in plain English for founders who run open-source software instead of paying a license, and what each asks you to do." canonical: "https://lopifi.com/savings/how-to/open-source-licenses" --- # Open-source licenses for founders replacing paid software > MIT, Apache, MPL, GPL and AGPL in plain English for founders who run open-source software instead of paying a license, and what each asks you to do. Source: https://lopifi.com/savings/how-to/open-source-licenses Part of: Lopifi — US GAAP books on autopilot, checked by a CPA (https://lopifi.com) --- Series: Move and replace. Reviewed 2026-10-25. Replacing a paid tool with open-source software removes a license fee and adds a license to follow. The terms are short and mostly about notices and sharing changes. This is a plain-English summary of the five you will meet, read from the Choose a License project. ## The five you will meet Summaries follow the Choose a License pages on the checked date. They describe the licenses in general; the text of the license in the repository is what governs. - MIT: permissive. You may use, change and distribute it commercially; keep the license and copyright notice. - Apache-2.0: permissive, with an express patent grant from contributors. Keep notices and state changes. - MPL-2.0: weak copyleft. Changes to the licensed files must stay available under the same license, while larger works that use them can have other terms. - GPL-3.0: strong copyleft. A distributed work must carry its source and the same license. - AGPL-3.0: strong copyleft that also treats offering a modified version over a network as distribution, so its users must be offered the source. ## What it means in practice Running an unmodified copy for your own team asks very little of you under any of these. The obligations start when you change the code and offer it to others, including customers using it over the web. That is the line to check before anyone customizes anything. Open source also has a cost that never shows in a license: someone has to patch it. Count the server, the backups, the updates and the person who owns them. The savings we report net those out. ## How we handle it We only name a project as open source when its repository's license resolves to a single standard id, and we show that id and the date we checked it. Projects with mixed or custom terms are not offered as open source. Before we run anything for you, you will see the license and what it asks of you in writing. ## Common questions ### Can a company use open-source software commercially? Open-source licenses generally allow commercial use. What differs is what you must do in return, from keeping a notice to publishing source for changes. Read the specific license, and ask counsel if you plan to modify and offer the software to others. ### What is special about the AGPL? The AGPL treats offering a modified version over a network as a trigger to make that version's source available to its users. Running an unmodified version for your own team does not change your code. If you change it, talk to counsel first. ### Is open source free? No. It means no license fee. You still pay for the server, backups, security updates and the time to run it. A saving is the old license minus all of that. ## Sources - [Choose a License: MIT](https://choosealicense.com/licenses/mit/) (read 2026-10-25) - [Choose a License: Apache-2.0](https://choosealicense.com/licenses/apache-2.0/) (read 2026-10-25) - [Choose a License: MPL-2.0](https://choosealicense.com/licenses/mpl-2.0/) (read 2026-10-25) - [Choose a License: GPL-3.0](https://choosealicense.com/licenses/gpl-3.0/) (read 2026-10-25) - [Choose a License: AGPL-3.0](https://choosealicense.com/licenses/agpl-3.0/) (read 2026-10-25) ## Keep going - [The honest math of self-hosting](https://lopifi.com/md/savings/how-to/self-hosting-honest-math): A formula for the real yearly cost of running open-source software yourself, a worked sample, and when you should not self-host. - [Dropbox migration, in depth](https://lopifi.com/md/savings/how-to/dropbox-migration): A start-to-finish plan for leaving Dropbox: inventory, destination, pilot, copy and verify, shared links, cutover, cancellation and how the books treat it. - [Offboarding SaaS accounts](https://lopifi.com/md/savings/how-to/offboard-saas-accounts): Remove a leaver's seats, shared logins and SSO access in order, keep their data with an owner, and put the freed licenses to work or cancel them. - [Export before you cancel](https://lopifi.com/md/savings/how-to/export-your-data-before-canceling-software): A checklist for exporting your data before you cancel a software subscription: what to pull, how to check it is complete, and what to keep for the books. - [Run the free audit](https://lopifi.com/savings/audit) - [All how-to guides](https://lopifi.com/md/savings/how-to) *General information, not tax, legal or accounting advice.*