Selecting a Software Licence?

indraneil asks: "I am a code monkey and have been so for close to 5 years now. I have recently been doing some self-started work that lets me design, implement and test stuff all by myself. A couple of people have liked my prototype and wanted to use it. I would be happy to let others use it, but I am unsure of what license to release it under. My CS course did not include any awareness of licensing and while I am aware of GPL, LGPL, Apache, BSD and Creative Commons licenses, I never got around to understanding them well enough to be able to form an opinion on what suits me best. I notice that SourceForge also expects me to specify my licensing choice, while I am setting up my project. If a person doesn't know about software licensing, where should they educate themselves about the ins and outs, so they can properly choose the license that is right for their project?"

Comments

Some good points

[orclevegam]

This guy has some good points and it's worth a read. Title of the article is "Pick a License, Any License"

http://www.codinghorror.com/blog/archives/000833.h tml

Short version:

[Daniel_Staal]

The short version:
BSD: Anyone can use your code, any way they want, as long as they mention your name.
GPL: Anyone can use your code, as long as they mention your name and allow others to use the code as you have let them use it.
LGPL: Same as GPL, but with some exceptions allowing others not to be bound to your licence if they don't actually touch your code in their project, but just use it.

Other licenses have variations on the above. In general I think most people should stick to one of those three, if for no other reason than to stop the confusion.

Pick the philosophy you like the best. That is the main point.

Re:Short version:

[dghcasp]

Funner version:

Public Domain: You want anyone to use your code free of restrictions. Nobody knows what you wear or what you eat. Your code is for simple binary trees and is published in University textbooks.

BSD: You want anyone to use your code, but not to blame you for it. You have medium hair and a T-shirt. Someone paid you less than minimum wage to write the code, and you use the money to eat at McDonalds. Your code is the TCP/IP protocol and is widely adopted and ubiqutous. Linux people think you're dead.

GPL: You wish everyone would use your code and share their modifications with the world. The only people who end up using it are Linux fanboys. You have long hair and a poncho. You spurn money and instead grow potatoes on your commune. Your code is the fourth non-completed conversion of an IBM PC game from the 1990s listed on sourceforge.

LGPL: You wish you could use the BSD licence, but are afraid the other people on the commune will throw potatoes at you.

Any other Licence: You either fail to realize that all other licences are basically the same as the BSD or GPL licence, or you contribute code to a project that has the same problem. You wear whatever everyone else wears and eat pasta because you heard it was "trendy." Your code calculates the phase of the moon on any past day using the Julian calendar because you can never remember the rules for converting from the Gregorian calendar.

Licensing 101

[pieterh]

If you are an individual or small team, the most important thing is to keep control over your copyright so you can make money from those people willing to pay for your work.

If you want to open source it, use the GPL and offer a commercial license opt-out. If you use the BSD, no-one will pay.

Do not accept any contributions unless people are willing to transfer (c) to you, or you cannot relicense your work.

Do not use GPL libraries, only BSD-licensed ones, or you cannot relicense your work.

If you are a team or company that does not want to make money from the software, license it under the BSD or Apache license.

GPL

[vga_init]

There are many software licenses to choose one, and everyone should have a license that does exactly what they want it to do. You don't even have to pick a preexisting one; write your own with the help of a lawyer (if you need it).

However, it sounds to me that your intention is to share this software with others. If you want to share it with just those individuals you choose, use some different license and have them sign an nondisclosure agreement or something (ps I am not a lawyer). If your intention, however, is to share your software with the public at large and have the community benefit as a whole, then please use the GPL.

The reason why the GPL is important for this purpose is that it makes your community software stay in the community. Lots of commercial enterprises use the GPL for reasons like this; they have valuable assets they want to give away (in the from of source code), but they don't want their competitors using it to screw them over--they want the world to benefit, and they themselves might benefit from seeing improvements to their code. That's the GPL.

If you use the GPL, not only will you be sharing your hard work with others in a way that you deem appropriate, you are also encouraging them to share their work with you. Whoever uses your project or develops it will assume a mutually beneficial role with everyone else who does the same, including you.

You know how they say...if you love something, set it free? You'd want to take some steps to ensure that it at least STAYS free, right?

Official commentary on the GPL

[datastew]

For the official Free Software Foundation (FSF) commentary on their GNU Public License (GPL) and other licenses, http://www.gnu.org/licenses/license-list.html is the place to start. The title of the page is: "Various Licenses and Comments about Them - GNU Project - Free Software Foundation (FSF)." I have referred to it often over the years.

License Education

[Secret Rabbit]

I find it hilarious that the OP asked how to educate him/her-self on this topic and immediately there are lots of post recommending a license (overwhelmingly the GPL); this is NOT what the OP asked for.

@OP:

If you want to educate yourself on what licenses would be appropriate for what /you/ want, read the licenses. This site:

http://opensource.org/

has a TONNE of them.

The most common are the BSD, MIT, MPL, Apache, GPL and LGPL. That is according to sf.net. Please note that there are licenses that don't just protect you, but seriously effect how others can use your work. Please consider this as well when choosing your license.

To add in my personal opinion, I *really* don't like the GPL. What it does is FORCE other developers that use your work (whether dynamically linked to or not) to use the GPL as well. My personal opinion is that as a developer, I don't have the right to choose the license of someone else's work. There is of course the argument that the developer just shouldn't use your work. But, IMO, that is a non-argument as in some areas there really is only one or two real options.

At any rate, agree or disagree. That's just my opinion.

Re:Junior achievement.

[aardvarkjoe]

This AC post is right -- you are going about this backwards. Your first question should not be "what license do I use?", it should be "what do I want to happen to my code?" Sit down and decide whether you want to give away the source code or not, whether you want to allow others to modify the code, whether you want to require modifications to be released to the public, and anything else that you think is important.

Once you've done that, picking a license is pretty straightforward. People have already posted links to a bunch of different places that compare licenses. Unless your requirements are pretty unusual, you should be able to find a license that matches them.

You have a few choices...

[nevali]

In order from least to most restrictive:

Use Public Domain if you don't care what people do with your code.

Use the MIT or X11 license if you want to give it as much chance as possible of being used by as many people as possible, without them being able to pass your code off as theirs.

The BSD (3-clause) license goes further by preventing other people from using you to endorse their products without your permission.

The LGPL ensures that the code will remain 'open' (i.e., distributing altered binaries means you have to distribute the matching sources). The LGPL specifically allows your code to be linked with, but not included in, non-LGPL projects. If your code isn't a library (or included in one), the LGPL isn't hugely different from the GPL, although releasing a program under the LGPL would mean somebody could turn it (or portions of it) into an LGPL-licensed library without any hassle.

The GPL is much the same as the LGPL, but doesn't contain any such provision for linking, so people linking with your code (if it's a library) had better make sure their do their homework first.

The GPL-compatible licenses (which includes PD, MIT/X11 and BSD) are so-called because they don't contain any restrictions beyond those included in the GPL. This means that your code, if released under a GPL-compatible license, can be legally be included in a GPL-licensed work: your code as you originally released it is still under the license you originally used, but the modifications and the derived work could be GPL'd.

Generally, the BSD license is a safe bet if you don't feel passionately about making sure that people who use your code must make their changes available to anybody who wants them, otherwise pick the LGPL or GPL depending on circumstance and requirements.

Avoid non-GPL-compatible licenses, especially home-grown ones: they usually end up doing nothing but preventing people who might want to use your code from doing so. Unless you're a huge multinational company, it's a sure-fire way to ensure that relatively few people will bother with what you've released (in which case, what was the point in releasing it?), and even then it'll stymie adoption.

Re:Important: you can change

[Arker]

One correction - you don't have to require copyright assignments to retain your ability to sell a proprietary product based on your own GPL product. All you have to require is a side-license on contributions - the contributors can still retain copyright on their own code, as long as they grant you a special license that allows you to use those contributions as you will.

Most will not mind doing this in order to get their code into the main tree and have you maintain it. It's a much less onerous requirement than a copyright assignment, but it's just as good for you.