Introduction to Open-Source Licenses

As a software developer, it is inevitable to deal with open source, either because you have to choose to use an open source product or you have to join open source. You may have thought about setting up a legal protection for your own open-source projects to protect the rights and interests of yourself and users, or if you use an open-source product, have you considered whether it can be abused freely because it is open source?

Unfortunately, in China, many people or even many enterprises don't care about the license (which is well known), which leads to a miserable situation where the Chinese software industry does not have major customers! So, since you are a developer, how can you indirectly lose your job without having to worry about the license?

Since dealing with open-source licenses is inevitable, let's take a look at several open-source licenses and further compare them.

Basically, each license has the following:

1. Grant of rights (authorization)
2. Redistribution (Redeploy)
3. Warranty (warranty)

As an open-source license, it grants you the right to use the source code for free and does not guarantee any quality. The biggest difference between each license lies in the second point, that is, redistribution. The following lists several different license features in redistribution.

License	Must Ship code	Combine with proprietary
GPL	Y	N
Lgpl	Y	Y
New BSD	N	Y
Apache Software License 2.0	N	Y

Combine with proprietary here means that you can integrate open-source products into your own products and then re-release them (that is, change the license ). As can be seen from the above table, GPL is very strict. Commercial software cannot include any product or component under the license in its final product, because the GPL license cannot be changed, this means that the source code containing the GPL component product must be public and GPL license. This is very inappropriate for the development of open-source class libraries. Imagine who dared to use such class libraries! With this in mind, lgpl has emerged, which allows the library to be released under other licenses, but requires the publisher to provide library extensible form or source code, therefore, the lgpl product will have source code no matter where it is located.

Lgpl is much loose than GPL, but it is still uncomfortable to require the source code to be included. In this case, you can choose a loose new BSD license or Apache Software License 2.0, there are basically no restrictions on the new BSD license. Apache Software License 2.0 defines contribution in more detail.

Here is a brief introduction and comparison of different licenses. For details, refer to the OSI website (www.opensource.org/licenses /)

In general, GPL is not recommended because it is too inflexible and everything is fixed.