This post summarizes characteristics of the different software licenses.
It is part of the post about types of free and open-source licenses..
Choosing a License
Each license is different, and they have different characteristics.
There is no perfect license for all situations. Depending on the context and intended use of software, there will be some characteristics that are sought while others are avoided. So it is important to identify what are the specific needs of the software, and then check them against the characteristics of the candidate licenses.
List of Characteristics of Software Licenses
Aspects covered in licenses that may be considered when comparing different open source licenses:
- Disclose source
- License & copyright notice
- Patent grant
- Sublicensing
- Trademark use
- Private use
- Network use distribution
- Compatibility
- Popularity
Patent grant
A patent claim is a claim to patent software. When a software is patented, it can be used only with the approval of the patent claimer, who may require for its use a fee at any time.
Patent grant is a characteristic of software licenses that implies that developers renounce explicitly to patent claims of their own contributions to the software or to the software when it is the result of collaboration between many developers.
Patent grant is a characteristic that benefits FOSS users, as it reduces the risks of patent claims, that may limit other software characteristics like free of cost or free distribution.
Patent treachery is an informal term, sometimes used by the Free Software Foundation, to refer to the act of patenting free and open software (FOSS), partly or entirely.
A Patent Assertion Entity (PAE), often called pejoratively patent troll, is a person or organization that deliberately patent else’s software or FOSS as its operation activity.
Patent hoarding is a term to refer to the regular activity of patenting else’s software or FOSS.
Take note that some popular licenses like MIT does not protect against patent claims.
Apache 2.0 is a permissive license that contains clauses against patent claims.
Sublicensing
Sublicensing is a characteristic of whether the integral or modified source code can be licensed with a different license.
Some licenses restrict sublicensing to specific licenses, for example:
- The GPLv2-or-above can only be sublicensed into GPLv3 or above.
- The European Union Public License can be sublicensed into a broad variety of licenses, but not any license
Public domain-equivalent or MIT license allows sublicensing without restrictions, because they do not have sublicensing clause.
Trademark use
Trademark use restricts whether the license claims trademark protection.
Apache 2.0 has trademark protection, while MIT has not.