The Free Desk · Free and Open-Source Software Explained

The signature of this desk

The Licence Decoder

Pick a licence — see what you may and may not do

Five licences cover almost everything you will ever download. Choose one and the panel says, in one line, what you are allowed to do with it — and what you are not.

GPL v2 / v3

You get the program and its source, and if you pass on a changed version you must pass on the same freedoms with it.

You may

Run it for anything, including at work. Read the source. Modify it. Give copies away or sell them.

You must

Ship the source alongside any binary you distribute, keep it under the same licence, and say what you changed.

You may not

Fold it into a closed product and keep your version secret. Nothing stops you selling it; something stops you closing it.

FAMILY: COPYLEFT · SEEN ON GIMP, BLENDER, AND MUCH OF THE GNU/LINUX USERLAND

MIT

Do almost anything you like with it, including selling it inside something closed, as long as the copyright notice travels with the code.

You may

Use, copy, change, merge, publish, sell. Keep your own changes private. Relicense your combined work.

You must

Keep the original copyright line and the licence text in copies and substantial portions.

You may not

Expect a warranty. The text disclaims one in capital letters, and courts have read it that way.

FAMILY: PERMISSIVE · THE DEFAULT FOR SMALL UTILITIES AND LIBRARIES

Apache 2.0

Permissive like MIT, but written by lawyers: it also hands you a patent licence from every contributor, and takes it back if you sue them.

You may

Use it commercially, modify it, distribute closed builds, and rely on an explicit patent grant.

You must

Keep the licence and any NOTICE file, and mark the files you changed.

You may not

Use the project's trademarks as your own, or keep the patent grant while suing a contributor over the same code.

FAMILY: PERMISSIVE, PATENT-AWARE · COMMON WHERE COMPANIES CONTRIBUTE TOGETHER

BSD 2 / 3-clause

The shortest of the serious licences: keep the copyright line, and — in the three-clause version — do not imply the authors endorsed you.

You may

Use, change and redistribute it in source or binary form, open or closed, free or paid.

You must

Reproduce the copyright notice and disclaimer in your source and in your documentation.

You may not

Use the project's or its authors' names to promote your build without written permission.

FAMILY: PERMISSIVE · OLD, SHORT, WIDELY COPIED

Proprietary freeware

It costs nothing and grants nothing. You are a guest under terms the owner writes, and can rewrite.

You may

Install and run it, usually for personal use only, for as long as the terms allow.

You must

Accept the agreement as written, including whatever it says about data collection and bundled extras.

You may not

Read the source, fix it yourself, pass it on, or usually use it commercially without buying a licence.

FAMILY: NOT OPEN SOURCE · “FREE TO DOWNLOAD” IS A PRICE, NOT A FREEDOM

The same five, side by side

Read the rows, not the reputations

Most arguments about licences turn out to be arguments about two cells in this table. The decoder above, this table and the grouping below are three views of the same five licences.

Permission	GPL v2 / v3	MIT	Apache 2.0	BSD 2 / 3-clause	Proprietary freeware
Use it for commercial work	Yes	Yes	Yes	Yes	Check terms
Read and modify the source	Yes	Yes	Yes	Yes	No
Redistribute your changed version	Yes	Yes	Yes	Yes	No
Keep your changes private	Only if unshared	Yes	Yes	Yes	n/a
Must publish source when you share it	Yes	No	No	No	n/a
Must keep notices and attribution	Yes	Yes	Yes	Yes	n/a
Explicit patent grant	v3 only	No	Yes	No	No

Summary only. The licence text governs, not this table — and nothing here is legal advice.

Organised by what you are allowed to do

The same five licences, grouped by permission

Permission 01

You may use it for anything

All five let you run the program for any purpose, at home or at work. This is the part nobody argues about.

·GPL v2 / v3 — yes, and you may sell copies
·MIT · Apache · BSD — yes, with no conditions on use
·Proprietary freeware — usually personal use only — read the terms

Permission 02

You must pass something on

Every open licence asks for something back. The size of the ask is the whole distinction.

·GPL v2 / v3 — the source, under the same licence
·Apache 2.0 — notices, and a record of what you changed
·MIT · BSD — the copyright line, and nothing more

Permission 03

You may not close it off

Only one family stops you shipping a secret version — and freeware stops you doing almost everything.

·GPL v2 / v3 — no closed derivatives you distribute
·MIT · Apache · BSD — closing it is permitted
·Proprietary freeware — no reading, no changing, no passing on

Free versus paid, argued both ways

Neither column wins outright

The case for free and open

The case for paid and closed

Cost

Nothing to pay, and nothing to renew.

A bill, but a defined one with a person on the other end.

Support

A forum, an issue tracker, and your own reading.

A support contract you can hold someone to.

Continuity

The source survives even if the project stops.

The vendor can withdraw it, and sometimes does.

Privacy

Usually less telemetry, and it is inspectable.

Varies wildly; a price tag is not a privacy policy.

Fit

You adapt to it, or you adapt it.

It is more likely to already do the specific thing you need.

Price is the least interesting difference between them. Accountability and exit are the interesting ones — who answers when it breaks, and what you keep if you leave.

Read the full argument →

The category shelf

Five shelves · what each is for, and what to look for

Almost every question about free software is really a question about a category. Learn the shelf once and the individual programs stop being a mystery.

Shelf 01

Browser

Everything else now happens here.

What to look forUpdate cadence, extension review, and what it does by default with your history.

Shelf 02

Office

Documents you will still need to open in ten years.

What to look forOpen file formats first; fidelity when someone sends you a proprietary one second.

Shelf 03

Media

Playing and making audio and video.

What to look forCodec breadth without a codec pack, and whether it wants to manage your library.

Shelf 04

Security

Passwords, encryption, backups.

What to look forA published audit, a clear threat model, and local-first storage.

Shelf 05

Creative

Images, 3D, audio production.

What to look forExport formats you can leave with, and a plugin ecosystem that outlives the app.

The categories worth knowing, in full →

Before you install

Six questions · step through them

01 Who publishes it?A named project, a company, or an anonymous mirror. The three carry different risks.
02 Where did this copy come from?The official page or an aggregator that wrapped an installer around it.
03 What licence is it under?It tells you whether you may keep using it, change it, or take it to work.
04 Is it still maintained?Look at the last release and the issue tracker, not the marketing page.
05 What does it ask for?Permissions, network access and telemetry, checked against what it needs to do the job.
06 Can you leave?Whether your data exports into a format something else can read.