Software license types and their intentions

[Dann Corbit]

There are lots of software license types, and they all have different intentions.

GPL license is intended to force you to share any modifications

LGPL license allows commercial software to use a library, but if you upgrade the library itself, then you must share the fixes.

Mozilla/Berkeley style licenses only ask that you give credit for using the software but you do not have to share your changes.

Public domain means that you can do absolutely anything with it in the USA. In Europe, the closest thing to that is "Creative Commons"

Ordinary copyright requires that you ask the author for any significant use of the code beyond "fair use".

So if you want to use software written by someone else, you should examine the digital rights for that software and see if it is the sort of thing that you are looking for.

All of these license types are valuable. All of them create useful and interesting projects. I have worked on projects in all of these categories. So pick and choose tools that fit your needs and the designs of your project.

IMO-YMMV

[Ras]

LGPL license allows commercial software to use a library, but if you upgrade the library itself, then you must share the fixes.

There's another right the user has: he must be able to modify the LGPL'ed library and still have the proprietary software run (provided, of course, that he didn't alter the lib in an incompatible way). That's why static linkage is not allowed.

[Dann Corbit]

LGPL license allows commercial software to use a library, but if you upgrade the library itself, then you must share the fixes.

There's another right the user has: he must be able to modify the LGPL'ed library and still have the proprietary software run (provided, of course, that he didn't alter the lib in an incompatible way). That's why static linkage is not allowed.

That sounds more like a duty than a right

[phhnguyen]

Recently I share some my codes under MIT license. It closes to Public domain but keep credit to the author.

[jdart]

The Apache license is also popular. Similar in intent to MIT/BSD, but addresses some topics such as patents that those other licenses do not.

--Jon

[Ras]

That sounds more like a duty than a right

The user must be able to do that - that doesn't mean that he is obliged.

For the authors who use a GPL'ed library, it is a duty to make that possible, of course, and that is the intent of the GNU licences.

[mar]

I like the boost license: http://www.boost.org/LICENSE_1_0.txt
It's short and explicitly states that

Code: Select all

The copyright notices in the Software and this entire statement, including
the above license grant, this restriction and the following disclaimer,
must be included in all copies of the Software, in whole or in part, and
all derivative works of the Software, unless such copies or derivative
works are solely in the form of machine-executable object code generated by
a source language processor.

This means that nobody who uses your sofware (library) needs to attach the license when distributing binaries of his program.
Giving credit isn't explicitly mentioned either so it's optional.

So you still have a license (public domain isn't acknowledged in all countries), source distributions/modificiations are required to contain the license so it still "protects" your code this way.

So my #1 choice for future (if any) open source projects of mine.

[jdart]

Boost has that clause because it is a library and it is intended to be bundled with other code.

--Jon

[mar]

Boost has that clause because it is a library and it is intended to be bundled with other code.

--Jon

Right, and I love that clause as it gives a lot of freedom to potential users.
And most (if not all) of the open source that people want to integrate are libraries.