I could license you to use this software, but then I’d have to kill you

If open source struck you as strange when you first heard of the concept, you don't know the half of it. Developers, exercising their legal right specify their own licensing terms, have come up with some pretty wacky stuff. Fact or fiction? Some software is only legal to use after you are dead.

Just shy of 2000 different licenses cover the 230,000+ projects in the Black Duck Knowledgebase. It's important to note that the top 10 licenses cover 93% of all projects and the top 20 almost 97%. Well over 60% are GPL.  So, the vast bulk of projects are under a small number of well-known licenses, and that's a good thing. But the other 3% of projects and 1980-odd licenses (and there are some odd ones!) clearly constitute a "long tail." Join me, won't you, for a journey to the outer reaches of that tail.

Some licenses just sound weird. A good example is the Iggy Wanna license. It sounds like a town in Pennsylvania, though I suspect it's probably a reference to Iggy Pop's I Wanna be your Dog. Beyond the title, the rest of the IWL reads like a normal license.

On the other hand, some licenses even read crazy. Among the craziest is the Do What the F**k You Want To Public License or WTFPL. The terms of that one read much like the title, though I am told by a lawyer that profanity aside, the author's intent is rather unambiguous.

Many licenses with normal sounding names include unusual terms. A number ask you to send money or provide to links to the author's website, usually (not always) on a voluntary basis. The Beer-Ware License reads:

<phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you can do whatever you want with this stuff. If we meet some day, and you think this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp

Does anyone ever meet the terms of a wacky license conditions like these? Oddly, yes. I know of a US software giant that met a license obligation by actually shipping a Fender Stratocaster guitar to one rockin' developer.

Also see:
Open source hardware gadgets
11 open source companies to watch

According to the Open Software Initiative, restricting use from a particular "field of endeavor" is a no-no in the open source world.  That clearly anticipates the EXT JS or "Tofu License" which prohibits use by anyone whose business uses animals in any way. Dairies, cosmetics companies, and circuses need not apply. There are lots of licenses (for example the Apple Public Source License) that don't restrict use per se, but to avoid liability include acknowledgement by the licensee that the software is not designed for use in a nuclear facility, aircraft or other life and death situation.

OK, speaking of life and death...yes, it's a fact: There is a Death and Repudiation License. The syck parsing kit is dual licensed under BSD License (Berkeley Software Distribution) and the D&R License. If you are not a BSD fan and chose the latter, you are subject to such conditions as:

ANY use of this software (even perfectly legitimate and non-commercial uses) until after death is explicitly restricted.

I always advise licensees to exercise caution, but this one deserves particular attention.