Open Source licenses compared

Sunday 16 October 2005 — This is more than 19 years old. Be careful.

I’ve decided to choose a real license for the software I post on this site, since responsible readers have asked me what license I use. I find the array of open source licenses baffling, so I dug up some resources:

Starting from the big bang, the Open Source Initiative has a comprehensive list of over 50 different licenses: The Approved Licenses. There’s no help here choosing one, but at least you can examine them in all their glory.
The Open Foundry has an interactive wizard, and a two-page comparison table. They consider 16 licenses on eight criteria. Both are hampered by imperfect English, but they present a lot of useful information.
Zack Rusin from KDE has a table comparing 15 popular licenses.
Whittling it down even further, David Wallace Croft compares six licenses on three criteria.
Finally, a lawyer explains the implications of some license choices.

After looking over all this, I’m choosing MIT. It allows others to do the most with the code I write. When I put myself in the user’s shoes, it’s the license I would want to see on code I wanted to use.

Comments

Myers Carpenter 2:20 PM on 16 Oct 2005

My friend zooko has a "Quick Reference For Choosing a Free Software License":

http://zooko.com/license_quick_ref.html

Ned Batchelder 3:47 PM on 16 Oct 2005

I looked at zooko's page, but found it unenlightening: I was confused by his presentation.

Stuart Langridge 5:00 PM on 16 Oct 2005

The MIT licence is what I use for the code I release, generally, for the same reasons as you -- it's a "go ahead and do what you want with this" licence. Most of the stuff I've written isn't so totally compelling that I could use it to further the cause of free software; if I GPLed my code and someone wanted to exploit it commercially then they'd write their own version.

same ground, different spin 5:17 PM on 16 Oct 2005

The GPL allows commercialization, though maybe not at exploitation levels you would be comfortable with...

DeanG 10:17 PM on 16 Oct 2005

What kept you from LGPL?

Ned Batchelder 6:48 AM on 17 Oct 2005

LGPL wants you to redistribute the source code, or to charge only a nominal copying fee. I write software for a living, and I charge money for that software. I intend to continue to keep that model as a possibility for myself in the future. It would be hypocritical of me to adopt a license that precludes that model for others.

Also, as Stuart says, the GPL and LGPL are designed to spread the philosophy of open source. I don't think my software is unique enough to do that.

Finally, in the spirit of sharing freely, I like the license model that restricts the least. Ironically, the GPL and even the LGPL place more restrictions on how the software can be used than the MIT license. I understand and even admire their philosophy, but it isn't right for me and the software I'm distributing.

Larry Hastings 10:29 PM on 18 Oct 2005

I prefer the zlib license. The only thing it doesn't explicitly permit is "sublicensing", but of course since the license itself is so totally open, people you propogate the software to can just accept the same license. Meanwhile, it has no documentation clause whatsoever; folks who use zlib-license software don't need to list the author's copyright anywhere but on the original sources.

What made you pick MIT over zlib?