Also, if the library is modified by someone else and passed on, the recipients should know that what they have is not the original version, so that the original author's reputation will not be affected by problems that might be introduced by others. Finally, software patents pose a constant threat to the existence of any free program. We wish to make sure that a company cannot effectively restrict the users of a free program by obtaining a restrictive license from a patent holder.
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To achieve this, non-free programs must be allowed to use the library. A more frequent case is that a free library does the same job as widely used non-free libraries. In this case, there is little to gain by limiting the free library to free software only, so we use the Lesser General Public License. In other cases, permission to use a particular library in non-free programs enables a greater number of people to use a large body of free software.
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Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. I can offer a service over the web, by using GPLed software. To remedy this, another license was born, the Affero General Public License , which requires anyone using the software to offer services to offer the source code to everyone that can access the services.
With classically distributed products, the case is different. If you do that, you have to offer the source code of any LGPLed components. If you are using GPLed components, you have to offer the source code of that component and anything that links against it.
Even my Android phone includes the GPL license in the about menu. This offer is valid for a period of three 3 years from the date of the distribution of this product by Sony Mobile. Finally, there is a replacement requirement for LGPLed libraries. It says that the user must be able to replace the LGPLed component with a modified version.
For a. NET library it means that the user must be able to put a modified version of the library in the directory of the application and have the application use that.
For example with AuthServices, it means that the user must be able to upgrade to a later, compatible release that contains security fixes, without the involvement of the vendor of the application.
Every now and then, I get a request to change the license of AuthServices to something else. First of all, it would be very hard to do that, as I would have to gain consent from all the developers that have contributed to the library.
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