What is the difference between permissive and copyleft licenses?

Permissive licenses like MIT and Apache let others use, modify, and distribute your code with almost no obligations beyond keeping the notice. Copyleft licenses like GPL require derivative works to be released under the same license, keeping them open.

When should I choose Apache 2.0 over MIT?

Apache 2.0 is like MIT but adds an explicit patent grant and a requirement to state significant changes, which gives users patent protection. Choose it for larger projects or where patent clarity matters; MIT is simpler for small libraries.

What does GPL v3 require?

GPL v3 is a strong copyleft license. Anyone who distributes your code or a modified version must make the full source available under GPL v3, and cannot add restrictions. It protects software freedom but limits use in closed-source products.

LGPL is a weaker copyleft aimed at libraries. You can link the library into proprietary software without that software becoming GPL, but modifications to the library itself must stay open under LGPL.

Is the generated text legally valid?

The texts are the official, unmodified license texts with only the name and year placeholders filled in, which is exactly how they are meant to be applied. For high-stakes projects you should still confirm the choice with a lawyer.

Open Source License Picker & Generator

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Choosing a software license decides how others may use your code. This tool compares the most common open-source licenses across permissions, conditions, and copyleft strength, then generates the full LICENSE text with your name and year filled in.

How it works

Each license falls on a spectrum from permissive to strong copyleft:

Permissive (MIT, BSD 3-Clause, ISC, Apache 2.0): use freely, just keep the notice. Apache 2.0 adds a patent grant.
Weak copyleft (MPL 2.0, LGPL v3): modifications to the licensed files stay open, but you can combine them with proprietary code.
Strong copyleft (GPL v3): any distributed derivative must be released under the same license.

The generator inserts your copyright holder name and the current year into the official, unmodified text — the standard, legally-meaningful way to apply a license.

Tips and notes

Permissive licenses maximize adoption; copyleft licenses maximize software-freedom guarantees.
Apache 2.0 is the safest permissive choice when patents could be in play.
For a library you want widely embedded, MIT or Apache 2.0 see the most uptake.
Always name the file exactly LICENSE (no extension) so GitHub detects it and shows the license badge.