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I'm currently evaluating which license to use for my next OS project, and things are getting more and more interesting after I decided that I really want to understand what the licenses mean.

Up until now, I just licensed everything under MIT because I like the MIT and their license is nice and short. And probably because it didn't really matter as only a hand full of people actually used my products.

But now, I'm at the brink of releasing something that will surely be used by many people and also be subject to major modifications, so I want to choose the right license to go with.

From what I understand, there are two groups of licenses; Copyright and Copyleft. Now, I read (and think to understand) MIT and BSD-2/3-Clause, but I'm really having trouble to get the gist of (L)GPL and alike.

My main problem is; I want to always be named in derivative works of my project. I don't really care if it's used proprietary or free, I just want to make sure that anyone who reads the code sees "ah, that's the original author" (referring to me).

Is there a clause in the copyleft licenses that assures this attribution? Or can this only be done using permissive copyright ones?

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If you don't care about the copyleft provisions, why are you considering those licenses? Almost all of the permissive licenses require attribution and are much simpler to comprehend. – Robert Harvey Sep 7 '11 at 15:37
up vote 5 down vote accepted

You need to remember the different between copyright and the license. If you write the code, you can always be named in the source files as the copyright holder, regardless of the license. If that is your only requirement, any license will do, it's choice has no bearing on that requirement.

The only slight clarification is that some licenses, like the BSD, forbid removal of the copyright sections. You might use that since it does state your requirement explicitly.

The thing with the GPL, is only use it because you understand the ethics of free software. Using the GPL is an ethical statement, rather than a means to make your software more popular.

Edit: The GPL is not an "open source" license, there's an important difference between open and free, it's not mere semantics. Preventing inclusion in a larger proprietary piece of software isn't primarily intended as a tool for competitive advantage, it's intended as a means to stop the proprietary software using the GPL software and not affording the freedoms that the GPL provides.

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Usage of the GPL can be much more than just an ethical statement. A company might use the GPL to release something that it wants (for some reason) released as open source but at the same time prevent competitors from using it in proprietary software. – user281377 Sep 7 '11 at 12:02
But let's say I release a library under GPL and put myself as the author in the sources - Doesn't that mean that anybody can remove my name and put his own in as the author? I know it wouldn't make a big difference, as he had to release it under GPL too, but it would put another person as the author who can then claim to have written the library? – Florian Peschka Sep 7 '11 at 12:06
@ApoY2k: No. You include a statement like "Copyright 2011, Joe Smith -- Offered under the terms of the GPL version 2. No warranties express or implied". Then section 1 of the GPL prohibits modifying or removing that notice, because it requires redistributors to "keep intact all the notices that refer to this License and to the absence of any warranty". – David Schwartz Sep 7 '11 at 14:04

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